PG-1605 Fix issue with test which crashes when re-run

We make sure to delete the keyring files before running the test.

contrib/pg_tde/t/2pc_replication.pl

@@ -28,6 +28,9 @@ sub configure_and_reload
 	return;
 }
 
+unlink('/tmp/pg_global_keyring.file');
+unlink('/tmp/pg_local_keyring.file');
+
 # Set up two nodes, which will alternately be primary and replication standby.
 
 # Setup london node