change the process of inserting a delay into the ast_answer() path so that we...

change the process of inserting a delay into the ast_answer() path so that we don't tell the calling channel that it has been answered unutil after the delay; for a single-thread call this won't matter all, but for a dual-thread call (using chan_local) this may fix the problem in issue 12924



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@127113 65c4cc65-6c06-0410-ace0-fbb531ad65f3