ApiPageTriageList: Guard against empty draftquality/copyvio condition
ApiPageTriageList: Guard against empty draftquality/copyvio condition

We were generating queries with:
WHERE [...] AND ptrp_deleted = '0' AND page_namespace = '0' AND ()

Change-Id: I3f8453cfe7d3d227ab89338846c2466c11e84c33

wikimedia/mediawiki-extensions-PageTriage,wikimedia/mediawiki-extensions-PageTriage,wikimedia/mediawiki-extensions-PageTriage