Clean up ast_json with ast_json_unref

git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@396143 f38db490-d61c-443f-a65b-d21fe96a405b
And get rid of another ast_bridged_channel()



git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@396145 f38db490-d61c-443f-a65b-d21fe96a405b