Update mcp_proxy_for_aws/sigv4_helper.py

Co-authored-by: wzxxing <169175349+wzxxing@users.noreply.github.com>
Signed-off-by: Kyon <91875365+kyoncal@users.noreply.github.com>

Author: kyoncal

mcp_proxy_for_aws/sigv4_helper.py

@@ -298,4 +298,4 @@ async def _inject_metadata_hook(metadata: Dict[str, Any], request: httpx.Request
 
         except (json.JSONDecodeError, KeyError, TypeError) as e:
             # Not a JSON request or invalid format, skip metadata injection
-            logger.info('Skipping metadata injection: %s', e)
+            logger.debug('Skipping metadata injection: %s', e)