properly report hangupcause when ast_request() fails for the last (or only)...

properly report hangupcause when ast_request() fails for the last (or only) target of a dial operation (issue #5394, different fix)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6735 65c4cc65-6c06-0410-ace0-fbb531ad65f3