Resizing issues

When resizing the window it throws an error in my Ubuntu machine:

```bash
terminate called after throwing an instance of 'std::out_of_range'
what(): Square which is (6; 9) is out of the board, (1-8;1-8).
Aborted (core dumped)
```

Reproduce the crash by resizing the window on Ubuntu, then trace the resize handling that produces the std::out_of_range error for square (6; 9). Confirm the fix by resizing repeatedly without an exception or abort.

Written by the indexing model from the issue text.