trailing missing value unrecognized

First thanks for this wonderful library. It's very fast comparing to other csv parsers.

The issue is when the reader parses the following line (note that this is the last line of the file), column size will be 4. The parser failed to find the trailing missing column:

ABC,123,123,123,\0

If there's an additional line, column size will be 5 which is correct:

ABC,123,123,123,\n\0