RequestResponseHolderListener fails if requestInitialized() is called more than once

Tomcat seems to call RequestResponseHolderListener.requestInitialized() more than once in some situations. I'm not sure if this is spec compliant.

Currently RequestResponseHolderListener fails with "There is already an instance bound to this thread" in this situation.

The implementation should be more robust and handle this case correctly.

See:
http://mail-archives.apache.org/mod_mbox/deltaspike-users/201507.mbox/%3C559E1F24.40408%40senat.fr%3E