app_voicemail: Fix enhancement that allowed multiple recipients in To: header

app_voicemail: Fix enhancement that allowed multiple recipients in To: header

An issue existed in r420577, which added multiple recipients to voicemail
emails. The patch, when looking at the intended recipients, looked ahead for
the '|' character inside a while loop which already had pulled out the
appropriate field parsing on the '|' character. This would cause it to skip
the recipients.

This patch fixes it such that it relies completely on the while loop to parse
through the e-mail fields.

Note that the original author of the patch looked at this fix and approved it.

ASTERISK-24250 #close
Reported by: abelbeck
patches:
  voicemail-420577-to-comma-fix.diff uploaded by abelbeck (License 5903)
........

Merged revisions 427585 from http://svn.asterisk.org/svn/asterisk/branches/13

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@427586 65c4cc65-6c06-0410-ace0-fbb531ad65f3