[FIX] mail-queue: Check the object retrieved from the database is a Zend mail message, i.e. if there was old data from pre Tiki 15 using ZF1 (thanks marclaporte)
[FIX] mail-queue: Check the object retrieved from the database is a Zend mail message, i.e. if there was old data from pre Tiki 15 using ZF1 (thanks marclaporte)

git-svn-id: a7fabbc6a7c54ea5c67cbd16bd322330fd10cc35@59488 b456876b-0849-0410-b77d-98878d47e9d5

oregional/tiki,tikiorg/tiki,oregional/tiki,oregional/tiki,tikiorg/tiki,oregional/tiki,tikiorg/tiki,tikiorg/tiki