save config on quitting Gajim. see #4174

src/gajim.py

@@ -384,6 +384,8 @@ def on_exit():
 	# delete pid file on normal exit
 	if os.path.exists(pid_filename):
 		os.remove(pid_filename)
+	# Save config
+	gajim.interface.save_config()
 	if sys.platform == 'darwin':
 		try:
 			import osx