Skip passing port in Host header if standard port.

[karrots]

Fixes #1361.

• This PR is compliant with the contributing guidelines (if not, please describe why).
• I have thoroughly tested my contribution.
• The code changes are reflected in the documentation at docs/en/*.

Rationale: Current HTTP module sends port in Host header even if using standard 80 and 443 ports. This fixes the behavior with the exception of HTTPS on port 80 and HTTP on port 443. A more thorough fix would take a bit of rework of the module.

Committers supporting this PR: leave blank

[djphoenix]

I think there should be "secure" flag check, not just omit both 80s and 443s

[karrots]

I did miss there was already a req->secure field in the structure. I'll update the code to check that.

[djphoenix]

IMHO if you point to RFC, you should use all of them :)

[karrots]

RFC only says leave it off if default. Never actually says the port should be there when it's not default, though. So it's a bit ambiguous.

[marcelstoer]

Thanks.