fix bug where only exception is passed to logger

notifications_utils/logging.py

@@ -141,6 +141,10 @@ class PIIFilter(logging.Filter):
         # and email addresses, masking them.  Ultimately this will probably get
         # refactored into a 'SafeLogger' subclass or something, but let's start here
         # with phones.
+
+        # Sometimes just an exception object is passed in for the message, skip those.
+        if not isinstance(msg, str):
+            return msg
         phones = re.findall("(?:\\+ *)?\\d[\\d\\- ]{7,}\\d", msg)
         phones = [phone.replace("-", "").replace(" ", "") for phone in phones]
         for phone in phones: