Fix chan_h323 compilation

This fixes the things in chan_h323 that were missed or ignored in the
great channel opaquification and gets chan_h323 back into a compiling
state.

(closes issue ASTERISK-22365)
Reported by: Dmitry Melekhov
Patches:
    chan_h323.patch uploaded by Dmitry Melekhov
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Merged revisions 398510 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 398511 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@398512 f38db490-d61c-443f-a65b-d21fe96a405b