Comment 21 for bug 1797814

Sorry - minor correction to my previous statement, it's an escape character (^[) not a NULL character.
I tested piping the same file.txt through a tr command to remove non-printable characters:

# tr -cd "[:print:]\n" < file.txt
2019-11-25 13:53:52.264 619 WARNING keystone.access_rules_config.backends.json [-] No config file found for access rules, application credential access rules will be unavailable.: FileNotFoundError: [Errno 2] No such file or directory: '/etc/keystone/access_rules.json'[00m
/etc/keystone/fernet-keys/ does not exist