Bug 17469: Add missing sample notices fr-CA test

Bug 17469: Add missing sample notices fr-CA test

Add fr-CA installer to xt/sample_letter.t

To test:
- Verify xt/sample_letter.t test checks fr-CA now and
  fails for just fr-CA.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Caitlin Goodger <caitlingoodger.student@wegc.school.nz>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 3c09fefb1dd3c8728404ef641f95885e61a674f4)
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>