Resigning at the very beginning causes a http panic

**Describe the bug**
Resigning at the very beginning of a match causes a panic and the bot does not respond to the user for the resign command.

**To Reproduce**
Steps to reproduce the behavior:
1. Start a new game
2. Don't make any moves
3. Mention the bot and resign

**Expected behavior**
The game should end with the other player being awarded the win. Alternatively, if there are no moves, simply "cancel" the game and don't declare a winner.

Start by reproducing the issue with a new game and the bot's resign command before any moves are made. Trace the resulting HTTP panic and verify that the command completes without a panic, either awarding the other player the win or canceling the game when no moves exist.

Written by the indexing model from the issue text.