Bug 18336: (follow-up) Shift TINYTEXT columns

Bug 18336: (follow-up) Shift TINYTEXT columns

This patch fixes two errors that slipped in the patchset.

To test:
- Create a dummy branch for testing:
  $ cd kohaclone
  $ git fetch
  $ git checkout v17.11.00 -b dummy
- Reset your working DB
  $ reset_all (y)
- Set your branch to current master
  $ git reset --hard origin/master
- Update the DB
  $ updatedatabase
- Update the schema files
  $ kshell
 k$ misc/devel/update_dbix_class_files.pl \
       --db_name koha_kohadev \
       --db_user koha_kohadev \
       --db_passwd password
 k$ exit
  $ git diff
=> FAIL: There are discrepancies on upgrades
- Reset to v17.11.00 revision and DB:
  $ git reset --hard v17.11.00
  $ reset_all (y)
- Set your branch to current master
  $ git reset --hard origin/master
- Apply this patch
- Update the DB
  $ updatedatabase
- Update the schema files
  $ kshell
 k$ misc/devel/update_dbix_class_files.pl \
       --db_name koha_kohadev \
       --db_user koha_kohadev \
       --db_passwd password
 k$ exit
  $ git diff
=> SUCCESS: No discrepancies!
- Reset to HEAD to get rid of the schema changes
  $ git reset --hard HEAD
- Regenerate the schema files on top of this patch
  $ dbic ; cd /home/vagrant/kohaclone
  $ git diff
=> SUCCESS: No discrepancies!
- Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>