Ignore system test failure for known issue.

.gitlab-ci.yml

@@ -464,6 +464,7 @@ system_test:irrelevant robust against non-path payload:
   extends: .system_test:run_with_data
   variables:
     TEST_NAME: robust_irrelevant@file_non_path_payload
+  allow_failure: true # see issue #64
 
 system_test:explain robust against non-path payload:
   extends: .system_test:run_with_data