Fix fastp merge issue with subworkflow

[pinin4fjords]

This fixes an issue in fastq_qc_trim_filter_setstrandedness inherited from its origin in nf-core/rnaseq. See nf-core/rnaseq#1452 for detail.

PR checklist

Closes #XXX

• This comment contains a description of changes (with reason).
• If you've fixed a bug or added code that should be tested, add tests!
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  • For modules:
    • nf-core modules test <MODULE> --profile docker
    • nf-core modules test <MODULE> --profile singularity
    • nf-core modules test <MODULE> --profile conda
  • For subworkflows:
    • nf-core subworkflows test <SUBWORKFLOW> --profile docker
    • nf-core subworkflows test <SUBWORKFLOW> --profile singularity
    • nf-core subworkflows test <SUBWORKFLOW> --profile conda

[jfy133]

Assuming the save_merged schema addition is a bonus bug fix?

[maxulysse]

nice catch

[pinin4fjords]

Assuming the save_merged schema addition is a bonus bug fix?

Not sure what you're getting at....