Fix stream procedure number for virDomainMigratePrepareTunnel3

The virDomainMigratePrepareTunnel3 impl in the remote driver
was using the procedure number for the virDomainMigratePrepareTunnel
method. This doesn't work out so well, because it makes the server
ignore & drop all stream packets

* src/remote/remote_driver.c: Fix procedure for PrepareTunnel3

src/remote/remote_driver.c

@@ -3691,7 +3691,7 @@ remoteDomainMigratePrepareTunnel3(virConnectPtr dconn,
     memset(&ret, 0, sizeof(ret));
 
     if (!(netst = virNetClientStreamNew(priv->remoteProgram,
-                                        REMOTE_PROC_DOMAIN_MIGRATE_PREPARE_TUNNEL,
+                                        REMOTE_PROC_DOMAIN_MIGRATE_PREPARE_TUNNEL3,
                                         priv->counter)))
         goto done;