push: Don't delay pipe termination

src/push.cpp

@@ -36,6 +36,9 @@ void zmq::push_t::xattach_pipe (pipe_t *pipe_, bool subscribe_to_all_)
 {
     // subscribe_to_all_ is unused
     (void)subscribe_to_all_;
+    //  Don't delay pipe termination as there is no one
+    //  to receive the delimiter.
+    pipe_->set_nodelay ();
 
     zmq_assert (pipe_);
     lb.attach (pipe_);