Removing a meaningless warning message.

Data in the queue and the socket are transmitted independently; special
READ_QUEUE and READ_SOCKET message types are used for synchronization.

The warning was accidentally committed with changeset 1d84b9e4b459.

src/nxt_unit.c

@@ -5764,10 +5764,6 @@ retry:
         nxt_unit_debug(ctx, "port{%d,%d} recv %d read_queue",
                        (int) port->id.pid, (int) port->id.id, (int) rbuf->size);
 
-        if (port_impl->from_socket) {
-            nxt_unit_warn(ctx, "port protocol warning: READ_QUEUE after READ_SOCKET");
-        }
-
         goto retry;
     }