mypy: fix missing attribute error

Timeout and RetryError expception doesn't return HTTP code, handle it in separate
except clause.

Signed-off-by: Martin Basti <mbasti@redhat.com>

atomic_reactor/plugins/check_base_image.py

@@ -149,10 +149,13 @@ def _get_manifest_list(self, image: ImageName) -> requests.Response:
 
             try:
                 config_blob = reg_client.get_config_from_registry(image, image.tag)
-            except (HTTPError, RetryError, Timeout) as ex:
+            except (HTTPError) as ex:
                 self.log.warning('Unable to fetch config for %s, got error %s',
                                  image, ex.response.status_code)
                 raise RuntimeError('Unable to fetch config for base image') from ex
+            except (Timeout, RetryError) as ex:
+                self.log.warning('Unable to fetch config for %s', image)
+                raise RuntimeError('Unable to fetch config for base image') from ex
 
             release = config_blob['config']['Labels']['release']
             version = config_blob['config']['Labels']['version']