dev-lua/lua-openssl: fix libressl build

backports libressl compat from master branch and disables
  cms, sm2 and srp.
Additionally set dependency to libressl < 2.7.0 because there
are changes in the libressl-2.7 api that raises
a lot of incompatible pointer types.

Closes: https://bugs.gentoo.org/667390
Signed-off-by: Matthias Hauber <[email protected]>
Signed-off-by: Michał Górny <[email protected]>
Closes: gentoo#10039