TODO: lib/whatweb/scan: print something more useful

[bcoles]

         # is it a valid domain?
          begin
            domain = Addressable::URI.parse(x)
            # check validity
            raise 'Unable to parse invalid target. No hostname.' if domain.host.empty?

            # convert IDN domain
            x = domain.normalize.to_s if domain.host !~ %r{^[a-zA-Z0-9\.:\/]*$}
          rescue => e
            # if it fails it's not valid
            x = nil
            # TODO: print something more useful
            error("Unable to parse invalid target #{x}: #{e}")
          end