srs reusable thread need join

@@ -235,7 +235,7 @@ namespace internal {
         // when thread terminated normally, also disposed.
         // we must set to disposed before the on_thread_stop, which may free the thread.
         // @see https://github.com/ossrs/srs/issues/546
-        disposed = true;
+        // disposed = true;
         
         handler->on_thread_stop();
         srs_info("thread %s cycle finished", _name);