Update python/activator/activator.py

Co-authored-by: Tim Jenness <[email protected]>

Author: hsinfang

python/activator/activator.py

@@ -524,7 +524,7 @@ def process_visit(expected_visit: FannedOutVisit):
 
 
 def invalid_visit(e: InvalidVisitError) -> tuple[str, int]:
-    _log.exception(e)
+    _log.exception("Invalid visit: %s", e)
     return f"Cannot process visit: {e}.", 422