disobedience/control.c: Force internal event when buttons are frobbed.

This fixes a bug leftover from fe0a1c48c648f683b3691132fb2b12b01d1ace32.

The obvious symptom is that the currently-playing track's progress
indication goes screwy when you use the pause button in the same
DisObedience instance.  (Other DisObediences work correctly, and all of
them work fine if you use some other mechanism to frob the pause
status.)

The bug is caused because the preemptive state update introduced in the
previous fix suppresses the internal event which used to raised once the
server acknowledged the state change.

Fix this by explicitly raising the relevant event.