net/haproxy 1.7.0 : libressl support

[Luca Pizzamiglio]

Hi guys,

I had to build haproxy 1.7.0 using openssl and libressl.
libressl support is not really provided, becuase of the
OPENSSL_VERSION_NUMBER issue between those two libraries.

In attachment there're two patches ready to be put in the files
directory and that solve (temporarily) the build issue.

Best regards
Luca

PS I didn't fill a PR because I'm not sure if those patches work in
all situation or with all options, so it's just a help for the
maintainer, but maybe not a solution.