Settings related to horizon plugins should be documented in individual
project repos. We support local_settings.d mechanism, so horizon plugins
can provide their own settings examples.
One example is SAHARA_AUTO_IP_ALLOCATION_ENABLED. This option has been
deprecated and replaced by another setting. It is hard for horizon team
to track this kind of changes.
This is just a change in the example local_settings.py and there is no
feature change, so there is no deprecation required.
Change-Id: Ib28110246567808f9e9c0f99c6032f7bdc931643
0659f9a98a