Avoid "bare except" in views/__init__.py

Flake8 complains about that.

views/__init__.py

@@ -352,7 +352,7 @@ class ImportSchemeConceptsView(ImportSchemeConceptsMixIn, EntityView):
             kwargs['delimiter'] = CSV_DELIMITERS[kwargs['delimiter']]
             try:
                 _handle_concepts_import(self._cw, entity, kwargs.pop('format'), **kwargs)
-            except:
+            except Exception:
                 # for unclear reason we have to pop stream from form data, else
                 # it's stored in session's data while it's not pickleable,
                 # leading to silent error in set_cookie with pyramid.