Merge #11884: Remove unused include in hash.cpp

Summary:
3f09e03 Remove unused include in hash.cpp (Karl-Johan Alm)

Pull request description:

Tree-SHA512: 543a72656460fba1c5498a0b85c49601d9b0399a4ecc49f4acf4715c258918da729df388e3be724c3161438e903ee16ad3c50626a71483aa6d85ffdbb827742d

Backport Core PR11884
https://github.com/bitcoin/bitcoin/pull/11884/files

Test Plan: make check

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D3208