message: can not use finish() in worker
diff: #include "swoole.h"
  #include "Server.h"
  -static swEventData *current_task;
  +static swEventData *current_task = NULL;
  static void swTaskWorker_signal_init(void);
  @@ -152,6 +152,11 @@ void swTaskWorker_onStop(swProcessPool *pool, int worker_id)
  int swTaskWorker_finish(swServer *serv, char *data, int data_len, int flags)
  {
  swEventData buf;
  + if (!current_task)
  + {
  + swWarn("cannot use finish in worker");
  + return SW_ERR;
  + }
  if (serv->task_worker_num < 1)
  {
  swWarn("cannot use task/finish, because no set serv->task_worker_num.");
  