Fix/table csv

When extracting to csv I encountered following exception.

```Traceback (most recent call last):
  File "extracttab.py", line 492, in <module>
    } [ args.t ](cells,args.page)
  File "extracttab.py", line 439, in o_table_csv
    tab[pg][j][i] = value
IndexError: list index out of range```

 I have no idea what was wrong inside method, but somehow contents of `l` got errorneously calculated. I fixed that.