Unstable OpenSSL strings exposed

[Zash]

LuaSec exposes some OpenSSL strings representing certificate chain validation conditions:

https://github.com/lunarmodules/luasec/blob/4c06287052d68fdbe7429b8f967cdc8ee94aa44a/src/context.c#L190

In https://github.com/openssl/openssl/commit/ade08735f9d0ac85d611c5abee8a1df651bbca13 one of these were changed, and in a discussion it was said that these strings should not be part of a public API as LuaSec makes them.