Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55799
Implement the restriction required by the JSR356 specification that only one message can be written to a remote endpoint at a time.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1543815 13f79535-47bb-0310-9956-ffa450edef68
Implement the restriction required by the JSR356 specification that only one message can be written to a remote endpoint at a time.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1543816 13f79535-47bb-0310-9956-ffa450edef68