chromiumWrapper creates two .desktop files (none with working icon)

I have ```chromiumWrapper``` in ```environment.systemPackages``` and
after ```sudo nix-channel --update``` and ```sudo nixos-rebuild switch``` today (== 33eced411fea68fd033a1fbd6de6b424b3af564b), I got two chromium .desktop files:

```
/run/current-system/sw/share/applications/chromium.desktop
/run/current-system/sw/share/applications/Chromium.desktop
```


The first file:

```
$ cat /run/current-system/sw/share/applications/chromium.desktop                                                                                                                                                                                                              
[Desktop Entry]                                                                                                                                                                                                                                                                
Type=Application                                                                                                                                                                                                                                                               
Exec=chromium %U                                                                                                                                                                                                                                                               
Icon=/nix/store/0ihj3f2prc20wf7rnipkmv1k6na9dbrx-chromium-stable-34.0.1847.116/share/icons/hicolor/48x48/apps/chromium.png                                                                                                                                                     
Comment=                                                                                                                                                                                                                                                                       
Terminal=false                                                                                                                                                                                                                                                                 
Name=Chromium                                                                                                                                                                                                                                                                  
GenericName=Web Browser                                                                                                                                                                                                                                                        
MimeType=                                                                                                                                                                                                                                                                      
Categories=Application;Network;WebBrowser;                                                                                                                                                                                                                                     
Encoding=UTF-8
```


The second file:

```
$ cat /run/current-system/sw/share/applications/Chromium.desktop                                                                                                                                                                                                               
[Desktop Entry]                                                                                                                                                                                                                                                                
Type=Application                                                                                                                                                                                                                                                               
Exec=chromium                                                                                                                                                                                                                                                                  
Icon=chromium                                                                                                                                                                                                                                                                  
Comment=An open source web browser from Google                                                                                                                                                                                                                                 
Terminal=false                                                                                                                                                                                                                                                                 
Name=Chromium                                                                                                                                                                                                                                                                  
GenericName=Web browser                                                                                                                                                                                                                                                        
MimeType=text/html;text/xml;application/xhtml+xml;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/mailto;x-scheme-handler/webcal                                                                                                            
Categories=Network;WebBrowser                                                                                                                                                                                                                                                  
Encoding=UTF-8
```

Both entries show up in the start menu (KDE Kicker?) but none of them have working icon. Annoying! :-)