chore: add debug message for delta (#654)

* chore: add debug message for delta

* Update server/src/http/refresher/delta_refresher.rs

Co-authored-by: Christopher Kolstad <chriswk@getunleash.io>

---------

Co-authored-by: Christopher Kolstad <chriswk@getunleash.io>

Author: sjaanus

server/src/http/refresher/delta_refresher.rs

@@ -16,7 +16,13 @@ impl FeatureRefresher {
         delta: ClientFeaturesDelta,
         etag: Option<EntityTag>,
     ) {
-        debug!("Got updated client features delta. Updating features with {etag:?}");
+        let updated_len = delta.updated.len();
+        let removed_len = delta.removed.len();
+
+        debug!(
+            "Got updated client features delta. Updating features with {etag:?}, updated {updated_len}, removed {removed_len}"
+        );
+
         let key = cache_key(refresh_token);
         self.features_cache.apply_delta(key.clone(), &delta);
         self.update_last_refresh(