When the system tray icon is created, qApp's setQuitOnLastWindowClosed
property is set to false, therefore do _not_ ignore widget close events, or
else wpa_gui will refuse to exit when the window manager is logging out.
While at it, remove WpaGui::fileExit() and connect fileExitAction to
quit().
Signed-off-by: Kel Modderman <kel@otaku42.de>
66897ae779