Bug 15486: Modify request.tt to handle the new error string

Bug 15486: Modify request.tt to handle the new error string

This patch makes reserve/request.pl display a convenient error
description when a hold cannot be placed due to the new daily limit
configuration.

To test:
- Apply this patchset
- Upgrade
- Configure your circulation rules so there's a daily limit for holds
- Place holds so the patron reaches the maximum
- Place one more hold
- Notice the hold cannot be placed and a convenient error message is
displayed.
- Sign off :-D

Signed-off-by: Séverine QUEUNE <severine.queune@bulac.fr>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>