res_pktccops needs to be able to export a symbol for chan_mgcp

(closes issue #16782)
 Reported by: nahuelgreco
 Patches: 
       res_pktccops.exports uploaded by nahuelgreco (license 162)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@246208 65c4cc65-6c06-0410-ace0-fbb531ad65f3