uniqueid: Update CHANGES to reflect new features

Note the new features provided by uniqueid in the
CHANGES file.

(issue ASTERISK-23120)
Review: https://reviewboard.asterisk.org/r/3316/
........

Merged revisions 410588 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@410589 f38db490-d61c-443f-a65b-d21fe96a405b
Prevent conflicts regarding unsolicited and solicited MWI to an endpoint.

If an endpoint is receiving unsolicited MWI for a mailbox and then attempts
to subscribe to an AOR that provides MWI for the same mailbox, then the SUBSCRIBE
is rejected with a 500 response.

Review: https://reviewboard.asterisk.org/r/3345
........

Merged revisions 410590 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@410591 f38db490-d61c-443f-a65b-d21fe96a405b