code: public URLNormalizer unsecureScheme() {
          Matcher m = PATTERN_SCHEMA.matcher(url);
          if (m.find()) {
              String schema = m.group(1);
              if ("https".equalsIgnoreCase(schema)) {
                  url = m.replaceFirst(StringUtils.stripEnd(schema, "Ss") + "$2");
              }
          }
          return this;
      }
docs: <p>Converts <code>https</code> scheme to <code>http</code>.</p>
  <code>https://www.example.com/ &rarr; http://www.example.com/</code>
  @return this instance