Venue data update for SDE3-LT421

[zwliew]

• Room Name: lt421
• Floor: 1
• Location: 1.297223428366857, 103.77105620935124

Venue does not exist in current version

Update proposed:

"SDE3-LT421": {
  "roomName": "lt421",
  "floor": 1,
  "location": {
    "x": 103.77105620935124,
    "y": 1.297223428366857
  }
}