manager: Unsubscribe from acl_change_sub at shutdown.

ASTERISK-24453 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/4110/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@426524 f38db490-d61c-443f-a65b-d21fe96a405b
res_fax: Resolve T38 gateway frame leak.

When frames are translated by a fax gateway they need to be freed.  The
existing call to ast_frfree was unreachable.  This change reorganizes
fax_gateway_framehook to ensure that ast_frfree is called when needed.

ASTERISK-24457 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/4115/
........

Merged revisions 426527 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@426528 f38db490-d61c-443f-a65b-d21fe96a405b