Catch only what you expect. We don't want to catch things like unknown...

Catch only what you expect. We don't want to catch things like unknown variables (and other programming errors) and SystemExit.

src/gtkgui_helpers.py

@@ -675,7 +675,7 @@ icon=gajim
 Description=xmpp
 ''' % command)
 					f.close()
-				except:
+				except IOError:
 					pass
 
 	try: