Fix xpand_transaction_replay configuration

The test expected rollbacks to be automatically replayed without it being
configured.

system-test/cnf/maxscale.cnf.template.xpand_transaction_replay

@@ -18,6 +18,7 @@ cluster=Xpand-Monitor
 user=maxskysql
 password=skysql
 transaction_replay=true
+transaction_replay_retry_on_deadlock=true
 
 [RCR]
 type=service