Removing duplicate entries in solutions list

The following entries were duplicates:
* "org.gnome.desktop.interface" 
* "org.gnome.nautilus" 

These duplicates propagated from the original installedSolutions.json file in pilotsConfig. See my pull request at https://github.com/Cloud4AllTUD/pilotsConfig/pull/7
Merge pull request #255 from cstrobbe/patch-7

Removing duplicate entries in solutions list