fix(_parse_job_results): Catch None details in response (#471)

fixes #470

Author: undodelete

panos/base.py

@@ -5168,7 +5168,7 @@ def _parse_job_results(self, show_job_xml, get_devices=True):
         else:
             try:
                 messages = job["details"]["line"]
-            except KeyError:
+            except (TypeError, KeyError):
                 messages = []
         if isstring(messages):
             messages = string_or_list(messages)