res_xmpp and res_jabber need to search 'cachable' in the attrib section of the received IE, not data.

(issue ASTERISK-20175)
(closes issue ASTERISK-21429)
(closes issue ASTERISK-21069)
(closes issue ASTERISK-21164)

Reported by: alecdavis
Tested by: alecdavis
alecdavis (license 585)

Review https://reviewboard.asterisk.org/r/2452/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@385939 f38db490-d61c-443f-a65b-d21fe96a405b