Commit patch from Paul Lange to fix a warning when installing the .desktop file.
Commit patch from Paul Lange to fix a warning when installing the .desktop file.

[Fixes bug #611372]

PintaProject/Pinta,Mailaender/Pinta,Fenex/Pinta,PintaProject/Pinta,PintaProject/Pinta,jakeclawson/Pinta,Fenex/Pinta,Mailaender/Pinta,jakeclawson/Pinta