Error when cancelling surround (block)

An error is raised when performing a keyboard interrupt:

```
E5108: Error executing lua: Keyboard interrupt
stack traceback:
        [C]: in function 'input'
        ...embrace.nvim/lua/embrace/surround.lua:118: in function 'match'
        ...embrace.nvim/lua/embrace/utils.lua:13: in function 'switch'
        ...embrace.nvim/lua/embrace/surround.lua:138: in function <.embrace/surround.lua:69>
```