Merged revisions 154066 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r154066 | tilghman | 2008-11-03 16:27:10 -0600 (Mon, 03 Nov 2008) | 5 lines
  
  Attempting to expunge a mailbox when the mailstream is NULL will crash Asterisk.
  (Closes issue #13829)
  Reported by: jaroth
  Patch by: me (modified jaroth's patch)
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@154072 65c4cc65-6c06-0410-ace0-fbb531ad65f3