Use "warn" log level for delivery errors

CHANGELOG.md

@@ -19,6 +19,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Return `202 Accepted` when activity is accepted by inbox endpoint.
 - Ignore forwarded `Like` activities.
 - Set 10 minute timeout on background job that processes incoming activities.
+- Use "warn" log level for delivery errors.
 
 ## [1.12.0] - 2023-01-26
 

src/activitypub/deliverer.rs

@@ -186,7 +186,7 @@ async fn deliver_activity_worker(
                 &activity_json,
                 &recipient.inbox,
             ).await {
-                log::error!(
+                log::warn!(
                     "failed to deliver activity to {} (attempt #{}): {}",
                     recipient.inbox,
                     retry_count + 1,