fixup: Update docs/testing_and_debugging.rst

Co-authored-by: Robert Raposa <rraposa@edx.org>

Author: dianakhuang

docs/testing_and_debugging.rst

@@ -76,4 +76,4 @@ file won't exist in devstack due to the local edx-platform copy overriding it.
 Any changes will need to be copied over into ``/py_configuration_files/(lms|cms).py`` to be tested
 on devstack.
 
-:: _public-dockerfiles logging configuration:https://github.com/edx/public-dockerfiles/blob/main/dockerfiles/edx-platform.Dockerfile#L262-L264
+:: _public-dockerfiles logging configuration: https://github.com/edx/public-dockerfiles/blob/75aa946f58b9d897ae1f738b2c89aefb1af09147/dockerfiles/edx-platform.Dockerfile#L262-L264