JS feedback

Author: norareidy

source/fundamentals/authentication.txt

@@ -297,7 +297,7 @@ following files:
 .. tip::
 
    To learn more about X.509 certificates, see
-   :manual:`X.509 </core/security-x.509/>` in the {+server+} manual.
+   :manual:`x.509 </core/security-x.509/>` in the {+server+} manual.
 
 To specify the ``MONGODB-X509`` authentication mechanism, set the
 ``mechanism`` field of your ``Credential`` struct to