Improve PaloAltoArp API error handling

Even if we do want a broad exception handler, never use just `except`,
as that will catch even low-level Python exceptions.  Added a noqa tag
and log the full exception with a slightly more information message.

python/nav/ipdevpoll/plugins/paloaltoarp.py

@@ -117,9 +117,10 @@ def creatorForNetloc(self, hostname, port):
                 ),
                 None,
             )
-        except:
-            self._logger.info(
-                "make sure the device is reachable and the key is correct"
+        except Exception:  # noqa
+            self._logger.exception(
+                "Error when talking to PaloAlto API. "
+                "Make sure the device is reachable and the API key is correct."
             )
             returnValue(None)