input focus is wrongly set when scrolling back to top and select any cell while freeze is configured

[keerthiprasath]

https://myliang.github.io/x-spreadsheet/

Steps to Reproduce:

1. In sheet 2(sheet-test), configure top 2 or more rows to freeze.
2. Scroll to end of list and click on any cell
3. Scroll back to top by click and drag scrollbar
4. Now select any cell below the freezed rows

The focus is offset to freezed rows.

[felicity23]

I found that too