knighttime_knifemare -> nighttime_knifemare

BUR #40944 has been approved by @nonamethanks.

rename knighttime_knifemare -> nighttime_knifemare

Fixing incorrect spelling. Source: https://www.youtube.com/watch?v=86iNkZsgyx4 (1:49)

I even checked before making the tag...

The bulk update request #40944 (forum #351308) has been approved by @nonamethanks.