DDSSEC_ — Matching of ParticipantStatelessMessage builtin endpoints

In §8.8.2.2:
"Discovered DomainParticipant entities that do implement the DDS Security specification, declare compatible Security Plugins and pass the Authentication protocol successfully shall be matched and the DomainParticipant shall also match ALL the builtin endpoints of the discovered DomainParticipant."

Prior to Authentication protocol success, the ParticipantStatelessMessage builtin endpoints should have been matched for the handshake protocol to occur. The above sentence suggests the matching of those builtin endpoints only occurs after Authentication succeed, which cannot happen without this matching.

The sentence could be rephrased as following:
"Discovered DomainParticipant entities that do implement the DDS Security specification, declare compatible Security Plugins and pass the Authentication protocol successfully shall be matched and the DomainParticipant shall also match all the builtin endpoints of the discovered DomainParticipant, except the ParticipantStatelessMessage builtin endpoints which are matched prior to the Authentication protocol."

Edit section 8.8.2.2 to clarify that ParticipantStatelessMessage is matched prior to authentication.

Make changes described in Revised Text.