Feel free to vote AYE to cancel. 

Given preimage was missing, the proposal will probably timeout. 

Cancel an ongoing referendum.

- `origin`: must be the `CancelOrigin`.
- `index`: The index of the referendum to be cancelled.

Emits `Cancelled`.

- People can vote to cancel something by saying "AYE".
- There was a missing preimage, which might make the proposal not work.
- The proposal might timeout if the missing preimage is not found.
- The post is saying that people can vote on something.
- The post is also saying that there was a problem with the proposal.

#288 Cancelling initial Decent Partners collective proposal as missing preimage.