fix pauseplay button icon update

When mouse click or keyboard press trigger play/pause, the button on osc interface don't update in time, this patch will fix it for better ux.

More info: mpv-player/mpv#8155 (comment)

mordenx.lua

@@ -1530,6 +1530,7 @@ end
 
 function pause_state(name, enabled)
     state.paused = enabled
+    mp.add_timeout(0.1, function() state.osd:update() end) 
     if user_opts.showonpause then
 		if enabled then
 			state.lastvisibility = user_opts.visibility