bug(secrets): add str() call to generate secret

Author: jslvtr

docs/docs/08_flask_jwt_extended/04_flask_jwt_extended_setup/README.md

@@ -66,5 +66,5 @@ def create_app(db_url=None):
 :::caution
 The secret key set here, `"jose"`, is **not very safe**.
 
-Instead you should generate a long and random secret key using something like `secrets.SystemRandom().getrandbits(128)`.
+Instead you should generate a long and random secret key using something like `str(secrets.SystemRandom().getrandbits(128))`.
 :::