Put the NNTP server name into Xref lines

RFC 5536 sec 3.2.14 says that the server-name in an Xref line is "which
news server generated the header field"; indeed, that is necessary for
newsreaders like gnus to handle references properly.  So pick up the server
name from the config if available (the first name if there's more than
one), from the host name otherwise, and use it rather than the domain
name of the list server.

Tests have been adjusted to match the new behavior.

0 files changed, 0 insertions, 0 deletions