[mpd] Add missing close for command pipe on deinit

src/mpd.c

@@ -4727,4 +4727,6 @@ void mpd_deinit(void)
   // Close pipes
   close(g_exit_pipe[0]);
   close(g_exit_pipe[1]);
+  close(g_cmd_pipe[0]);
+  close(g_cmd_pipe[1]);
 }