Change gc tab icon when we lose the room connection.

Thanks to Heather Gilmore, my wife, for grey-scaling the image. :-*

src/groupchat_control.py

@@ -269,8 +269,10 @@ class GroupchatControl(ChatControlBase):
 		if self.attention_flag and gajim.config.get('show_unread_tab_icon'):
 			tab_image = img_16['message']
 		else:
-
-			tab_image = img_16['muc_active']
+			if gajim.gc_connected[self.account][self.room_jid]:
+				tab_image = img_16['muc_active']
+			else:
+				tab_image = img_16['muc_inactive']
 		return tab_image
 
 	def update_ui(self):

src/roster_window.py

@@ -2208,7 +2208,7 @@ _('If "%s" accepts this request you will know his or her status.') % jid)
 		for state in ('connecting', 'online', 'chat', 'away', 'xa',
 				'dnd', 'invisible', 'offline', 'error', 'requested',
 				'message', 'opened', 'closed', 'Not in Roster',
-				'muc_active'):
+				'muc_active', 'muc_inactive'):
 
 			# try to open a pixfile with the correct method
 			state_file = state.replace(' ', '_')