Fix retracting UserTune/UserActivity

gajim/common/modules/user_activity.py

@@ -87,8 +87,10 @@ class UserActivity(AbstractPEPModule):
         return activity_dict or None
 
     def _build_node(self, data):
-        activity, subactivity, message = data
         item = nbxmpp.Node('activity', {'xmlns': self.namespace})
+        if data is None:
+            return
+        activity, subactivity, message = data
         if activity:
             i = item.addChild(activity)
             if subactivity:

gajim/common/modules/user_tune.py

@@ -81,8 +81,10 @@ class UserTune(AbstractPEPModule):
         return tune_dict or None
 
     def _build_node(self, data):
-        artist, title, source, track, length = data
         item = nbxmpp.Node('tune', {'xmlns': nbxmpp.NS_TUNE})
+        if data is None:
+            return item
+        artist, title, source, track, length = data
         if artist:
             item.addChild('artist', payload=artist)
         if title: