Bug 30761: Fix typos in OPAC reset password template

Bug 30761: Fix typos in OPAC reset password template

This patch corrects the word "PLease" to "Please." The patch also adds
some periods at the end of some alert strings to make punctuation
consistent between different alerts.

To test, an inspection of the patch is probably enough. The main fix
(the "PLease") only appears when an unknown error occurs.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>