F58: fix link tag (#4608)

Co-authored-by: Mike Gower <[email protected]>

Author: momdo

techniques/failures/F58.html

@@ -56,7 +56,7 @@
 
          <ul>
             <li> 
-              <a href="https://www.rfc-editor.org/rfc/rfc9110#name-redirection-3xx">RFC 9110: HTTP Semantics 15.4. Redirection 3xx</li>
+              <a href="https://www.rfc-editor.org/rfc/rfc9110#name-redirection-3xx">RFC 9110: HTTP Semantics 15.4. Redirection 3xx</a></li>
 
          </ul>