Update metadata-for-codeql-queries.rst

Replace link to blog with trackable GH.io link

docs/codeql/writing-codeql-queries/metadata-for-codeql-queries.rst

@@ -49,7 +49,7 @@ The following properties are supported by all query files:
 |                       | | ``warning``             |                                                                                                                                                                                                                                                                                                                                                                       |
 |                       | | ``recommendation``      |                                                                                                                                                                                                                                                                                                                                                                       |
 +-----------------------+---------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
-| ``@security-severity``| ``<score>``               | Defines the level of severity, between 0.0 and 10.0, for queries with ``@tags security``. For more information about calculating ``@security-severity``, see the `GitHub changelog <https://github.blog/changelog/2021-07-19-codeql-code-scanning-new-severity-levels-for-security-alerts/>`__.                                                                       |
+| ``@security-severity``| ``<score>``               | Defines the level of severity, between 0.0 and 10.0, for queries with ``@tags security``. For more information about calculating ``@security-severity``, see the `GitHub changelog <https://gh.io/2021-07-19-codeql-security-severity>`__.                                                                                                                            |
 +-----------------------+---------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 
 Example