use gtk_combo_box_set_qmodel to reduce code

This work is alreayd done for us in this utility function.
Aditionally we no longer need to filter disabled account protocols
since AIX has been removed.

Change-Id: I2cc4812c95be5ee0e87b8292d6b289f30ef992d4
Reviewed-by: Nicolas Jäger <nicolas.jager@savoirfairelinux.com>
1 file changed