minor #9778 Fixed build and link to the recommended article to exclude logs (javiereguiluz)

This PR was squashed before being merged into the 4.1 branch (closes #9778).

Discussion
----------

Fixed build and link to the recommended article to exclude logs

This fixes the build on Travis CI and recommends the new feature to exclude log files instead of the existing feature which will be deprecated soon.

Commits
-------

091695a Fixed build and link to the recommended article to exclude logs

Author: javiereguiluz

logging.rst

@@ -341,9 +341,14 @@ Learn more
     logging/channels_handlers
     logging/formatter
     logging/processors
-    logging/monolog_regex_based_excludes
+    logging/monolog_exclude_http_codes
     logging/monolog_console
 
+.. toctree::
+    :hidden:
+
+    logging/monolog_regex_based_excludes
+
 .. _Monolog: https://github.com/Seldaek/monolog
 .. _LoggerInterface: https://github.com/php-fig/log/blob/master/Psr/Log/LoggerInterface.php
 .. _`logrotate`: https://github.com/logrotate/logrotate

logging/monolog_regex_based_excludes.rst

@@ -6,6 +6,12 @@
 How to Configure Monolog to Exclude 404 Errors from the Log
 ===========================================================
 
+.. tip::
+
+    Read :doc:`/logging/monolog_exclude_http_codes` to learn about a similar
+    but more generic feature that allows to exclude logs for any HTTP status
+    code and not only 404 errors.
+
 Sometimes your logs become flooded with unwanted 404 HTTP errors, for example,
 when an attacker scans your app for some well-known application paths (e.g.
 `/phpmyadmin`). When using a ``fingers_crossed`` handler, you can exclude