Undefined index: alignment

[DMGPage]

Hello!
Working with your library, I encountered some issue:

shuchkin/simplexlsx/src/SimpleXLSXEx.php:268
Undefined index: alignment

I don't really know, how this file was made, but it always creates this error. I added example of the file in attachment.
import_6391894ae8e46.xlsx

[DMGPage]

Just want to remind you, that issue still exists in version 1.0.19. Also I found out, that issue appears with files, created by Google Sheets.

[shuchkin]

fixed in master branch