Update session_redis/session.py

Co-authored-by: Florent Xicluna <142113+florentx@users.noreply.github.com>

session_redis/session.py

@@ -97,9 +97,8 @@ class RedisSessionStore(SessionStore):
             "utf-8"
         )
         if self.redis.set(key, data):
-            if not isinstance(expiration, int):
+            if not (expiration and isinstance(expiration, int)):
                 expiration = DEFAULT_SESSION_TIMEOUT_ANONYMOUS
-            if expiration == 0:
                 expiration = DEFAULT_SESSION_TIMEOUT_ANONYMOUS
             return self.redis.expire(key, expiration)