use py3 compatible except syntax (#39569)

passerelle_montpellier_sig/models.py

@@ -50,7 +50,7 @@ class MontpellierSig(BaseResource):
                                             resp.status_code))
         try:
             return resp.json()
-        except Exception, e:
+        except Exception as e:
             logger.warning('error occured while trying to read json data from %r: %r', endpoint, e)
             return []