Fix an error when pasting from .xls file#349

sonmansu wants to merge 1 commit intonick-keller:masternick-keller/react-datasheet-grid:masterfrom

sonmansu:fix-error-when-copy-from-xls-filesonmansu/react-datasheet-grid:fix-error-when-copy-from-xls-fileCopy head branch name to clipboard