Failing to save correct detector name

When using built-in detectors in config file

detectors: ["ET_Triangle_EMR"]

and placeholder

file_name: "E-{{ detectors }}_STRAIN-1000000-1024.gwf"

the final file naming should be:

"E-E1_STRAIN-1000000-1024.gwf"

and not:

"E-E1_Triangle_EMR_STRAIN-1000000-1024.gwf"