[cleanup] add confval role to entry for ``linkcheck_allow_unautho…

…rized`` (#12177)

CHANGES.rst

@@ -89,7 +89,7 @@ Bugs fixed
 * #11715: Apply ``tls_verify`` and ``tls_cacerts`` config to
  ``ImageDownloader``.
  Patch by Nick Touran.
-* #11433: Added the ``linkcheck_allow_unauthorized`` configuration option.
+* #11433: Added the :confval:`linkcheck_allow_unauthorized` configuration option.
  Set this option to ``False`` to report HTTP 401 (unauthorized) server
  responses as broken.
  Patch by James Addison.