empty error messagestack on error multiple v_dbio_command columns found;

[torvista]

Due to sloppy copying and pasting, a products csv for import had two v_dbio_command columns. The import was aborted as reported in the log:

2020-08-30 13:06:43: importGetHeader, multiple v_dbio_command columns found; import cancelled.

However, the messagestack error was empty.

[lat9]

Note, an additional message was added for this case. Translated versions will require update!