Fix network-manager-applet startup issue 'GLib-GIO-Message: Using the 'memory' GSettings backend.  Your settings will not be saved or shared with other applications.'

(cherry picked from commit 51dc1ddb7c6e974e36c1a2d8701fbc7c254cbc72)

Conflicts:
	pkgs/tools/networking/network-manager-applet/default.nix