rows.go Scan() crashes if no arguments

[khanzf]

If the SELECT of a query does not contain any arguments, such as
SELECT FROM table WHERE ....
then the Scan() function crashes on what is currently line 69:
for i, col := range r.rows[r.pos-1] {
I suspect this is because r.pos is 0, so minus 1 is -1, which results in an index error.