Don't show oldname -> newname for unstaged modifications

I found a way to fix issue https://github.com/ndbroadbent/scm_breeze/issues/144.

This changes the output of git status from
```
# On branch: master  |  +1  |  [*] => $e*
#
➤ Changes to be committed
#
#        renamed: [1] "foo bar" -> test 
#
➤ Changes not staged for commit
#
#       modified: [2] "foo bar" -> test  
#
```
to
```
# On branch: master  |  +1  |  [*] => $e*
#
➤ Changes to be committed
#
#        renamed: [1] "foo bar" -> test 
#
➤ Changes not staged for commit
#
#       modified: [2] test 
#
```
This enables adding the modifications via `git add 2`.