for RID_SVXSTR_SINGLENUM_DESCRIPTIONS, but since
71b35212, we're
allowing here more than 8 items. So don't try to get
strings for those items, the same way we
restrict that in SvxNumValueSet::SetNumberingSettings.
(Although these string are (still) not used anywhere
AFAIK.)

Change-Id: Iaa538e4aebfc72729646f0befc7bcf8e58d6cbee