1 Followup for bug#9011  - New value after value mapping can't be 0.
Squashed commit of the following:

commit 712dcc7977bf28801613c41d703288b291635aaa
Merge: e7e3e49 8355e19
Author: Carlos Rodriguez <carlos.rodriguez@otrs.com>
Date:   Thu Feb 13 03:50:14 2014 -0600

    Merge branch 'rel-3_3_bug#9011' of github.com:s7design/otrs into s7design-rel-3_3_bug#9011

commit 8355e19e8b3ae2079942b006b7c123800373cf66
Author: s7design <otrs@s7designcreative.com>
Date:   Mon Feb 3 08:14:08 2014 +0100

    Change operator || to // because this operator will check if the variable is defined or nor

commit 1d420609bcad8fc1d18106b66e0f126192340b5f
Author: s7design <otrs@s7designcreative.com>
Date:   Fri Jan 31 17:59:20 2014 +0100

    [Bug 9011]

    New value after value mapping can't be 0.