logger: only flatten dicts if all keys are strings
This avoids blowing up when passing complex arguments (e.g. full snapshots) to logging.debug
Test Plan
tox
Migrated from D2271 (view on Phabricator)
Staging instance, all changes can be removed at any time
This avoids blowing up when passing complex arguments (e.g. full snapshots) to logging.debug
tox
Migrated from D2271 (view on Phabricator)