Website crashed if number of cols or number of rows is not set

[roschro-fau]

• If there is no value in one of the fields "Number of Columns" and "Number of Rows" in the QR Code form and you click complete the results on the download page are not shown
• The "required" tag should be added to both fields
• if there is no value in one of the fields the "Complete" Button should not be clickable