Bug 10507: improve warning about duplicate patron attribute value

Bug 10507: improve warning about duplicate patron attribute value

If a warning about a duplicated patron attribute is returned,
the value was being passed back for display in the warning
message with the same name as the variable in errors

As the message is displayed in the context of errors
the error value 1 was being displayed not the value
duplicated as intended.

Pass the value to the template with a unique name.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
I fixed another tiny typo while signing off: "is already in use" instead
of "is already is use."

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Passes koha-qa.pl, works as advertised.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 2614e07e1e2e6386b5f91e65f127940072e54d4d)
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>