Bug 24803: Remove JS error when clicking "Log in to your account"

Bug 24803: Remove JS error when clicking "Log in to your account"

This patch removes the "data-toggle" attribute from the login link in
order to avoid a JavaScript error. Since we have a custom click handler
to trigger the modal we don't need Bootstrap's "automatic" modal
handling.

Test plan:
1. Apply patch
2. Open F12 dev tools
3. Click "Log in to your account" on OPAC
4. Observe no Javascript errors in console

Signed-off-by: David Cook <dcook@prosentient.com.au>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>