Handle empty lines in CTDL-ASN csv import

[woodkri]

Currently if there's a row with no "@type" it returns. Should continue to the next item in the for loop instead.

[tim-eduworks]

Excel adds empty lines to csv files when saved. Stalls import. Empty row confirmed in Notepad++, deleted and works fine after. Excel is the main tool used to create or edit csv for most people, needs to ignore the row as there is no fix for Excel process.