Generated xlsx file with column range out of bounds

[islotwin]

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Problem: Generated xlsx file in alasql has more columns in range than actual data. The same file passed through another program (i.e. google docs) returns right number of columns.
I think it comes from the fact, that in alasql columns are indexed starting with 0 (https://github.com/agershun/alasql/blob/develop/src/15utility.js#L1153). However, the end range is calculated basing on columns.length (https://github.com/agershun/alasql/blob/develop/src/833xlsx.js#L123). So, end range is actually out of bounds. Is it intended behavior?

Example: For file with data in columns "A" and "B" expected range would be "A:B". Received range is "A:C".

Reproduction: https://jsfiddle.net/mujsr8zy/6/

File passed through google spreadsheets: example-2.xlsx

[mathiasrw]

Released as part of https://github.com/AlaSQL/alasql/releases/tag/v2.0.1