2dfe455161 Remove mention of core2 (Tobin C. Harding)
Pull request description:
We no longer depend on `core2`, remove stale code comment mention of the crate.
Fix: #2034
ACKs for top commit:
Kixunil:
ACK 2dfe455161
apoelstra:
ACK 2dfe455161
Tree-SHA512: cb723a384cd69e5b1aa70bdb25f53c818092c465783bd8a9b1ec60af488ed013d39f29057b4b09d6347b8bc52911eb6daf609bd088dec172647dbfedc2ea1791