correct application launcher name for gthumb

defaults/main.yml

@@ -8,7 +8,7 @@ application_starters:
   - libreoffice-draw
   - xfce-display-settings
   - xfce4-screenshooter
-  - gthumb
+  - org.gnome.gThumb
   - simple-scan
 
 application_default_favorites:
@@ -24,7 +24,7 @@ application_default_favorites:
   - xfce4-screenshooter
   - simple-scan
   - fotowall
-  - gthumb
+  - org.gnome.gThumb
 
 install_fotowall: true
 install_cewe_fotobuch: false