Update api.env

Author: pavelzotikov

test/integration/api.env

@@ -7,7 +7,9 @@ MONGO_HAWK_DB_URL=mongodb://mongodb:27017/hawk
 # Events database URL
 MONGO_EVENTS_DB_URL=mongodb://mongodb:27017/hawk_events
 
-
+# Redis URL (optional, for TimeSeries metrics)
+# If not set, Redis features will be disabled gracefully
+REDIS_URL=redis:6379
 
 # MongoDB settings
 MONGO_RECONNECT_TRIES=60