Infinite loop when calling :CBlbox

[balazser]

Hi @LudoPinelli, I noticed when I want to comment out in a box the following snippets and in some other cases comment-box.nvim and nvim gets frozen. Probably caused by an infinite loop. Reproduce call :CBlbox on line on this code snippet:

        #  using imperative code
        #  ────────────────────────────────────────────────────────────
        i = 0
        for c in range(3):
            j = i + cnt[c]
            nums[i:j] = [c] * cnt[c]
            i = j