Fix notify_on_all_muc_messages I just broke, remove useless and unclear function

src/chat_control.py

@@ -561,7 +561,8 @@ class ChatControlBase(MessageControl):
 			if self.type_id  == message_control.TYPE_GC:
 				gc_message = True
 			if not gc_message or \
-			(gc_message and other_tags_for_text == ['marked']):
+			(gc_message and (other_tags_for_text == ['marked'] or \
+			gajim.config.get('notify_on_all_muc_messages'))):
 			# we want to have save this message in events list
 			# other_tags_for_text == ['marked'] --> highlighted gc message
 				type_ = 'printed_' + self.type_id

src/groupchat_control.py

@@ -326,9 +326,6 @@ class GroupchatControl(ChatControlBase):
 
 		menu.show_all()
 
-	def notify_on_new_messages(self):
-		return gajim.config.get('notify_on_all_muc_messages')
-
 	def on_treeview_size_allocate(self, widget, allocation):
 		'''The MUC treeview has resized. Move the hpaned in all tabs to match'''
 		self.hpaned_position = self.hpaned.get_position()

src/message_control.py

@@ -68,10 +68,6 @@ class MessageControl:
 		# NOTE: Derived classes MUST implement this
 		pass
 
-	def notify_on_new_messages(self):
-		# NOTE: Derived classes MUST implement this
-		return False
-
 	def repaint_themed_widgets(self, theme):
 		pass # NOTE: Derived classes SHOULD implement this