fix up master advisory, advisories are only fired after broker is fully started so the nowMaster advisory needs to ocurr after start rather than as part of persistence adapter start, resolves org.apache.activemq.broker.ft.QueueMasterSlaveTestSupport#testAdvisory failures
activemq/trunk/activemq-broker/src/main/java/org/apache/activemq/broker/BrokerService.java