Fix issues with strict syntax

[nvnieuwk]

The plugin should be properly tested with the new strict syntax. Issues are starting to pop up:

• Cannot pass booleans on command-line with strict syntax nextflow#6760 (comment)

[just-simon-5]

Thanks for adding this! (leaving a comment so i get notified 😁)

[nvnieuwk]

#197 fixes the StackOverflowError 🥳