Simon Willnauer cb4eebcd6a Make index in TermsLookup mandatory (#25753)
This change removes the leniency of having a `null` index to fetch
terms from in 6.0 onwards. This feature will be deprecated in the 5.x series
and 6.0 nodes will require the index to be set.

Closes #25750
2017-07-17 18:50:30 +02:00
..
2017-03-30 22:26:10 -04:00