forceSecureConnection invalid?

I have:

“forceSecureConnection”: true

in my Default.json – and I get an error message  that this is invalid.  I’m running at moment in the IDE – is it that I can only use this on a server w/ an ssl cert installed (if that is the case I would expect a different error message…)  See pic.

Or did the name change for the config value?  Or something else?

Thanks much

Matthew