logger: reduce stack size, which got freed in 05a771152520

commit msg: 'logger: avoid uORB::Subscription, directly use orb_subscribe() instead'

src/modules/logger/logger.cpp

@@ -204,7 +204,7 @@ int Logger::start(char *const *argv)
 	logger_task = px4_task_spawn_cmd("logger",
 					 SCHED_DEFAULT,
 					 SCHED_PRIORITY_MAX - 5,
-					 3800,
+					 3600,
 					 (px4_main_t)&Logger::run_trampoline,
 					 (char *const *)argv);