s3: fix malformed endpoint URL from older versions

this is specifically for linode, but may apply for other storages too

src/storage/s3.js

@@ -46,7 +46,8 @@ function S3_NOT_FOUND(error) {
 }
 
 function formatError(error) {
-    return `code: ${error.Code} message: ${error.message} HTTP: ${error.$metadata.httpStatusCode}`;
+    // $metadata can be undefined if HTTP request was never sent
+    return `code: ${error.Code} message: ${error.message} HTTP: ${error.$metadata?.httpStatusCode}`;
 }
 
 const RETRY_STRATEGY = new ConfiguredRetryStrategy(10 /* max attempts */, (/* attempt */) => 20000 /* constant backoff */);