Bug 35185: Remove is_html flag from sample notices that are plain text

Bug 35185: Remove is_html flag from sample notices that are plain text

Some notices had the is_html flag for new installations, but actually
didn't include any HTML formatting. These should be plain text
to have the line breaks behave as expected.

This updates:
* 2FA_OTP_TOKEN
* OPAC_REG_VERIFY

We cannot do a database update here, as libraries will
have changed and updated these. So this is only for new
installations.

To test:
* Apply patch
* reset_all (create a new sample database)
* Verify that the HTML checkbox is not set for these notices
* Verify they appear as plain text notices, not including HTML tags

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit c6284eed812eb4de52738e845b662e199f58fd1a)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>