logger: increase stack size

evaluated with: logger start -e -t -m all
and then make sure to get an error printf in the mavlink writer backend,
eg. for an ack timeout.

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,
-					 3200,
+					 3800,
 					 (px4_main_t)&Logger::run_trampoline,
 					 (char *const *)argv);