Revert "Fix Neovim .desktop file to open files from GUI file manager (#2233)"

This reverts commit 479f20d294.

applications/nvim.desktop

@@ -2,7 +2,7 @@
 Name=Neovim
 GenericName=Text Editor
 Comment=Edit text files
-Exec=sh -c "$TERMINAL --class=nvim --title=nvim -e nvim -- %F"
+Exec=$TERMINAL --class=nvim --title=nvim -e nvim -- %F
 Terminal=false
 Type=Application
 Keywords=Text;editor;