[xlsx import] removed the QVector::reserve() calls with the size equal to the...
requested to merge work/527-excel-import-crash-when-saving-a-project-with-text-data-in-the-spreadsheet into master
[xlsx import] removed the QVector::reserve() calls with the size equal to the total number of columns to be imported, the vectors are resized later properly when adding the relevant column data pointers only.
fix #527 (closed)