[js] Browser.supported false positive check on react native

`js.Browser.supported` returns `true` in react native environment which in turn leads to crash in `HttpJs`, 63 where protocol is determined: `js.Browser.location.protocol.toLowerCase(); `

Suggestion is either update `js.Browser.supported` so that it will be a bit smarter and also check relevant properties of `window` like `location`, or add `try...catch` into HttpJs for this particular case (although I wonder where else false-positive `js.Browser.supported` might produce unwanted results.