[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

docs/user_guide.rst

@@ -445,7 +445,7 @@ Logging
 ~~~~~~~
 
 Tox logs its activity inside `.tox/<env_name>/log` which can prove to be a good
-source of information when debugging its behaviour. It should be noted that
+source of information when debugging its behavior. It should be noted that
 some of the environment variables with names containing one of the words
 ``access``, ``api``, ``auth``, ``client``, ``cred``, ``key``, ``passwd``,
 ``password``, ``private``, ``pwd``, ``secret`` and ``token`` will be logged