Trouble building lang/ruby27 and lang/ruby30

Hi.

I was going through the process of upgrading from 13.0-RELEASE to 
13.1-RELEASE, and when building the ports ruby27 and ruby30, both failed 
on account of some .html files not existing under a "capi" directory in 
the work directory. I got past the bug by disabling C API documentation 
in their make configs.

I apologize that I did not document the errors before they were lost 
behind my terminal's history limit, but I hope that this information can 
be useful anyway.


Bradley