Make the dbus plugin not sleep unless the event queue is empty, hopefully

reduce latency when running many dbus commands.
(cherry picked from commit d66e529d85b9f8111f04519559abb1446e3323d7)
Signed-off-by: Jean-Paul Saman <jean-paul.saman@m2x.nl>

modules/control/dbus.c

@@ -839,7 +839,9 @@ static void Run          ( intf_thread_t *p_intf )
 {
     for( ;; )
     {
-        msleep( INTF_IDLE_SLEEP );
+        if( dbus_connection_get_dispatch_status(p_intf->p_sys->p_conn)
+                                             == DBUS_DISPATCH_COMPLETE )
+            msleep( INTF_IDLE_SLEEP );
         int canc = vlc_savecancel();
         dbus_connection_read_write_dispatch( p_intf->p_sys->p_conn, 0 );