ext/digest/rmd160 was referencing a function that never existed in openssl.
The name was simply mistyped. Now it can use openssl.

openssl was always linked to ext/digest when library is avaiable,
even when it was disable by configure option and not used by code.

upstream refs: https://bugs.ruby-lang.org/issues/10252
upstream refs: https://bugs.ruby-lang.org/issues/10324

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

minitest can live without gems. Just a minor fix to
solve a require that fails when gem is missing

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

rdoc seems to be written to run without gem. However,
some internal code still does not check for gems presence.
With a small patch, rdoc can run without gems.

Ref: https://bugs.ruby-lang.org/issues/10196

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>