Validate stage of Pipeline crashes when processing two files that can't be validated

[simon-20]

Brief Description
We've observed three times that the validate stage of the Pipeline crashes when it encounters the two files that are causing validation problems, see here: IATI/js-validator-api#544

Normally, the validate stage of the Pipeline just times out, and passes over these files. But three times last week it crashed and hung, and as a result, stopped all data from proceeding through the Pipeline.

Not yet sure why this crash sometimes occurs.