vmount run at default priority

src/drivers/vmount/vmount.cpp

@@ -443,7 +443,7 @@ int vmount_main(int argc, char *argv[])
 		thread_should_exit = false;
 		int vmount_task = px4_task_spawn_cmd("vmount",
 						     SCHED_DEFAULT,
-						     SCHED_PRIORITY_DEFAULT + 40,
+						     SCHED_PRIORITY_DEFAULT,
 						     1900,
 						     vmount_thread_main,
 						     (char *const *)argv + 1);