"quit and shutdown" menu item available even when not connected to dameon

[Calum]

In non-classic mode without being connected to a daemon the 'quit and shutdown' is available and will generate an error when selected.

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/deluge/ui/gtkui/menubar.py", line 256, in on_menuitem_quitdaemon_activate
    self.window.quit(shutdown=True)
  File "/usr/lib/python2.7/dist-packages/deluge/ui/gtkui/mainwindow.py", line 163, in quit
    client.daemon.shutdown()
  File "/usr/lib/python2.7/dist-packages/deluge/ui/client.py", line 504, in __call__
    return self.daemon.call(self.base, *args, **kwargs)
AttributeError: 'NoneType' object has no attribute 'call'

[Calum]

Fix committed to 1.3-stable: ​b530658e