Show 'Indexing by robots' status correct on action=info

When $wgNamespaceRobotPolicies contains a noindex for a namespace and
the page contains __INDEX__, the index status on action=info was
"Disallowed", but that is wrong, because the page is indexed.

Pass the 'index' to the robot policy logic.

Change-Id: Ib77c3e73968cdc72f657e50371a2372564a1c618