fix: https://issues.apache.org/jira/browse/AMQ-4674

add transport options "?transport.hbGracePeriodMultiplier" which is used to add a user defined grace period to the read check interval indicated by the connecting STOMP client. 

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1514023 13f79535-47bb-0310-9956-ffa450edef68