Add messaging server requires the path=* subresources if a server already exists

There were several changes to Messaging subsystem, the user now is required to add path=* subsresources in addition to the server in a composite operation. If there is no server, the path=* subresources are optional. Previously the user was able to add additional servers with no path=* subresources, although the additional server would not work, because they would conflict with the default path=* used by the existing server.