CI: The "cross-build" job doesn't have EVP_MD_CTX_new

[Hal Murray]

> I assume it's from this change: https://gitlab.com/NTPsec/ntpsec/-/commit/
> 7c8b5fe20eafe911be4eac64467a032a52753313#887b5ad6972aa02f9a0434c248cd872a9
> 94e6fc5_44_41 

Thanks.  Yes.  That would explain this problem.

But that cleanup went in back in June.  Why didn't we notice this problem 
earlier?



> Ubuntu 16.04 is pretty old, does it need to be supported?

Good question.  Any opinions?
There are also 14.04 and 18.04
Are there any other distros supporting old old old versions that we might 
run into?

Do we have a web page that describes our support policy?

My vote is that we support versions that are publicly supported and don't 
support old versions that are suppported for fee.  That's not so much that 
we aren't interested in old versions but that they aren't interested in 
us.  We should consider support for an old version on a case by case basis 
if there is ever any interest.  Who knows, somebody might get interested 
in NTS.


I think the fix is only 3 or 4 lines in 2 places.

Does #ifdef work on functions?  I thought not, but the old code looks like 
its doing that.


-- 
These are my opinions.  I hate spam.