Bug 7944 - attribute error could be clearer

Bug 7944 - attribute error could be clearer

If you try to create a patron and enter an extended attribute value
which is required to be unique but exists in another record the error
you receive is not clear. It uses the attribute code instead of the
description. This patch adds description to the output.

To test you must have ExtendedPatronAttributes enabled.

- Edit or create an extended patron attribute and designate it a unique
  identifier.
- Edit a patron and add a value to that attribute.
- Edit another patron and try to add the same value.

You should get an error which includes both the description of the
attribute you tried to modify and the value you submitted.

Signed-off-by: Christopher Brannon <christopher@debian.brannon.org>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, no problems found.
Passes tests and Qa script.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>