Move setting of voicemail zonetag and locale up a bit.

Move setting of voicemail zonetag and locale up a bit.

The voicemail [general] zonetag and locale variables weren't loaded
until after the mailboxes were initialized. This caused the settings to
be unset for those mailboxes until a reload was performed.

(closes issue ASTERISK-18838)

Review: https://reviewboard.asterisk.org/r/1570
Reviewed by: Matt Jordan
........

Merged revisions 347111 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@347124 65c4cc65-6c06-0410-ace0-fbb531ad65f3