Due to Blazegraph limits, it is no longer a good idea to keep categories in the same namespace as main wikidata namespace. We should create a separate instance of Blazegraph, and have categories in that instance instead.
Migration plan after we have 2 instances running:
[x] Create new namespace on category instance
* Update configs with CATEGORY_ENDPOINT pointing to new instance. Note that this will also switch crons to update new instance, so better to do far away from daily cron run.
* [[ https://wikitech.wikimedia.org/wiki/Wikidata_query_service#Data_reload_procedure | Load weeklies and dailies ]]
* Update categories alias to new namespace
* Switch nginx to use new instance (nginx config patch)
* Update cron scripts in puppet to use new endpoint
* Drop categories namespace on main instance