Point develop.element.io to our Element Call + LiveKit experiment (#2…

…5636)

This is an experimental version of Element Call using a LiveKit SFU that we'd like to start dogfooding and gaining confidence on internally, so the current plan is to trial it on develop.element.io and Nightly for a while.

element.io/develop/config.json

@@ -44,7 +44,7 @@
  "feature_video_rooms": true
  },
  "element_call": {
- "url": "https://element-call.netlify.app"
+ "url": "https://element-call-livekit.netlify.app"
  },
  "map_style_url": "https://api.maptiler.com/maps/streets/style.json?key=fU3vlMsMn4Jb6dnEIFsx"
 }