Fix logical subscriber wait in test.

Buildfarm members sungazer and tern revealed this deficit.  Back-patch
to v10, like commit 4f10e7ea, which
introduced the test.

src/test/subscription/t/002_types.pl

@@ -554,8 +554,7 @@ e|{e,d}
 # which needs an active snapshot in order to operate.
 $node_publisher->safe_psql('postgres', "INSERT INTO tst_dom_constr VALUES (11)");
 
-$node_subscriber->poll_query_until('postgres', $synced_query)
-  or die "Timed out while waiting for subscriber to synchronize data";
+$node_publisher->wait_for_catchup($appname);
 
 $result =
   $node_subscriber->safe_psql('postgres', "SELECT sum(a) FROM tst_dom_constr");