roster_tweaks.correct deactivating plugin(remove added buttons)

roster_tweaks/roster_tweaks.py

@@ -75,6 +75,8 @@ class RosterTweaksPlugin(GajimPlugin):
     def deactivate(self):
         gajim.interface.roster.status_combobox.show()
         self.status_widget.destroy()
+        self.activity_button.destroy()
+        self.mood_button.destroy()
 
     def on_ctrl_m(self, accel_group, acceleratable, keyval, modifier):
         menubar = gajim.interface.roster.xml.get_object('menubar')