Fix removing events when scrolled to bottom

gajim/chat_control_base.py

@@ -1237,7 +1237,7 @@ def _on_edge_reached(self, scrolledwindow, pos):
                 if not app.events.remove_events(self.account, jid,
                 types=types_list):
                     self.redraw_after_event_removed(jid)
-            elif self.session and self.session.remove_events(types_list):
+            elif not app.events.remove_events(types_list):
                 # There were events to remove
                 self.redraw_after_event_removed(jid)