Fix redeclaration of variables when using IMAP storage

(closes issue #11988)
Reported by: jaroth
Patches:
      variable_cleanup.patch uploaded by jaroth (license 50)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@103737 65c4cc65-6c06-0410-ace0-fbb531ad65f3