Calling repairDatabase on collections containing too-long index keys silently drops all indexes on non-MMAPv1 storage engines

Affects WT on 3.0+ and InMemory on 3.2+. MMAPv1 is not affected.

Collections containing long index keys that are inserted when failIndexKeyTooLong=false will have all indexes dropped after running repairDatabase if failIndexKeyTooLong is changed back to the default value of true.