Codestyle enhancements

app/auth/routes.py

@@ -69,8 +69,7 @@ def register():
             os.makedirs(user.path)
         except OSError:
             current_app.logger.error(
-                'Make dir {} led to an OSError!'.format(user.path)
-            )
+                f'Make dir {user.path} led to an OSError!')
             db.session.delete(user)
             db.session.commit()
             abort(500)