fix ascat Rscript calling

[ggabernet]

Somehow this was not properly fixed, it threw me an error again when running on AWS

PR checklist

• This comment contains a description of changes (with reason)
• If you've fixed a bug or added code that should be tested, add tests!
• If necessary, also make a PR on the nf-core/sarek branch on the nf-core/test-datasets repo
• Ensure the test suite passes (nextflow run . -profile test,docker).
• Make sure your code lints (nf-core lint .).
• Documentation in docs is updated
• CHANGELOG.md is updated
• README.md is updated

Learn more about contributing: CONTRIBUTING.md

[maxulysse]

I have a feeling, I've seen this PR before.
Looks strangely a lot like #127
Before looking more into this one, are you sure your dev branch is sync to the nf-core dev branch?

[maxulysse]

It seems I got some old code when I merge some #131
Sorry about that

[ggabernet]

sure, thanks! I also didn't see it on the last review...