[3.6] bpo-9146: Raise a ValueError if OpenSSL fails to init a hash func (#3274)

[3.6] bpo-9146: Raise a ValueError if OpenSSL fails to init a hash func (#3274)

* [3.6] bpo-9146: Raise a ValueError if OpenSSL fails to init a hash func. (GH-1777)

This helps people in weird FIPS mode environments where common things
like MD5 are not available in the binary as a matter of policy.
(cherry picked from commit 07244a83014fad42da937c17d98474b47a570bf7)

* Include a NEWS entry.