Bug 12106: fix capitalization: "Patron Attributes" on tools/patron import

Bug 12106: fix capitalization: "Patron Attributes" on tools/patron import

There are three instances of incorrectly-capitalized "Patron Attributes"
on the patron import page. This patch corrects them.

To test, view the patron import page (Tools -> Import patrons). Confirm
that instances of the phrase "patron attributes" in the bottom-most
fieldset are correctly capitalized.

Followed test plan, works
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>