14691 add documentation for gunicorn bug (#14924)

* 14691 add documentation for gunicorn bug

* Update docs/installation/4-gunicorn.md

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Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

docs/installation/4-gunicorn.md

@@ -58,3 +58,6 @@ You should see output similar to the following:
     If the NetBox service fails to start, issue the command `journalctl -eu netbox` to check for log messages that may indicate the problem.
 
 Once you've verified that the WSGI workers are up and running, move on to HTTP server setup.
+
+!!! note
+    There is a bug in the current stable release of gunicorn (v21.2.0) where automatic restarts of the worker processes can result in 502 errors under heavy load. (See [gunicorn bug #3038](https://github.com/benoitc/gunicorn/issues/3038) for more detail.) Users who encounter this issue may opt to downgrade to an earlier, unaffected release of gunicorn (`pip install gunicorn==20.1.0`). Note, however, that this earlier release does not officially support Python 3.11.