When doing a built-in blind or attended transfer, restore the ability to use '#'

When doing a built-in blind or attended transfer, restore the ability to use '#'
to terminate the number and immediately do the transfer instead of having to
dial the number and just wait for the feature digit timeout.
(issue #8366, xueliangliang)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@59886 65c4cc65-6c06-0410-ace0-fbb531ad65f3