chore: add default value for redis configuration (#9864)

api/.env.example

@@ -31,8 +31,17 @@ REDIS_HOST=localhost
 REDIS_PORT=6379
 REDIS_USERNAME=
 REDIS_PASSWORD=difyai123456
+REDIS_USE_SSL=false
 REDIS_DB=0
 
+# redis Sentinel configuration.
+REDIS_USE_SENTINEL=false
+REDIS_SENTINELS=
+REDIS_SENTINEL_SERVICE_NAME=
+REDIS_SENTINEL_USERNAME=
+REDIS_SENTINEL_PASSWORD=
+REDIS_SENTINEL_SOCKET_TIMEOUT=0.1
+
 # PostgreSQL database configuration
 DB_USERNAME=postgres
 DB_PASSWORD=difyai123456