Be more liberal accepting ADD_EDGE messages with conflicting local address information.

Be more liberal accepting ADD_EDGE messages with conflicting local address information.

If the ADD_EDGE is for one of the edges we own, and if it is not the
same as we actually have, send a correcting ADD_EDGE back. Otherwise, if
the ADD_EDGE contains new information, update our idea of the local
address for that edge.

If the ADD_EDGE does not contain local address information, then we
never make a correction nor log a warning.