IVR allows for invalid selection of the voicemail context zonemessages

If you have a voicemail.conf file with the context of zomemessages in it and it's in the following order:
[general]
[zonemessages]
[default]

The IVR menu will default to the voicemail context of zonemessages for the directory service. zonemessages is a system context and should not be available for selection.