[PR aio-libs#12133/4ec897bd backport][3.13] Update Gunicorn documentation link (aio-libs#12134)

**This is a backport of PR aio-libs#12133 as merged into master
(4ec897b).**

Co-authored-by: laurent b <metter2ooo@gmail.com>

Author: patchback[bot]

docs/logging.rst

@@ -130,7 +130,7 @@ Example of a drop-in replacement for the default access logger::
 
 Gunicorn access logs
 ^^^^^^^^^^^^^^^^^^^^
-When `Gunicorn <http://docs.gunicorn.org/en/latest/index.html>`_ is used for
+When `Gunicorn <https://gunicorn.org>`_ is used for
 :ref:`deployment <aiohttp-deployment-gunicorn>`, its default access log format
 will be automatically replaced with the default aiohttp's access log format.