[FTS] UI: API created index definition has fts.js JSON parse problem

Found by Marty Schoch [X]

Here's the problematic index definition...

https://gist.github.com/mschoch/60068e94a712d348f8ac445fd71d3e90

It displays ok in the list view, but in the edit view, there's a JS parse exception...

https://gist.github.com/mschoch/dc506ef7980b52d16d0115cf40a4684c

Used to work in older builds (but not sure if spock or classic UI)