redraw partipiant list after maximizing the conference. Fixes #6961

src/roster_window.py

@@ -3390,6 +3390,9 @@ class RosterWindow:
                 mw.window.window.focus(gtk.get_current_event_time())
             return
         ctrl = gajim.interface.minimized_controls[account][jid]
+        # redrawing partipiant list
+        sw = ctrl.xml.get_object('list_scrolledwindow')
+        sw.queue_draw()
         mw = gajim.interface.msg_win_mgr.get_window(jid, account)
         if not mw:
             mw = gajim.interface.msg_win_mgr.create_window(ctrl.contact,
@@ -6409,7 +6412,7 @@ class RosterWindow:
         # it means we are waiting for this number of accounts to disconnect
         # before quitting
         self.quit_on_next_offline = -1
-        
+
         # groups to draw next time we draw groups.
         self.groups_to_draw = {}
         # accounts to draw next time we draw accounts.