suppress warnings of URI.extract

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46503 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/uri/generic.rb (check_port): allow strings for port= as
  described in rdoc.

* lib/uri/rfc3986_parser.rb (regexp): implementation detail of above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46504 b2dd03c8-39d4-4d8f-98ff-823fe69b080e