Bug 13795: Remove occurences of unused columns in code

Bug 13795: Remove occurences of unused columns in code

These patch removes these two columns from backfill_statstics script
and from columns.def - this file is used to create description in guided
reports

Test plan:
1. Run installer/data/mysql/backfull_statistics.pl
--> without this patch, there are associatedborrower and usercode errors
reported
--> with patch, these two columns are not reported

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>