Unregister the chat service on destroy.

shell/model/BuddyModel.py

@@ -139,7 +139,4 @@ class BuddyModel(gobject.GObject):
 	def __buddy_current_activity_changed_cb(self, buddy, activity=None):
 		if not self._buddy:
 			return
-		if activity:
-			self.emit('current-activity-changed', activity)
-		else:
-			self.emit('current-activity-changed')
+		self.emit('current-activity-changed', activity)

shell/view/ActivityHost.py

@@ -150,6 +150,6 @@ class ActivityHost:
 
 	def _activity_closed_cb(self, shell, activity):
 		if activity == self:
-			self.chat_hide()
+			self._chat_window.destroy()
 			self._frame_was_visible = False