Bug 23210: (follow-up) Log in for tags link should trigger modal

Bug 23210: (follow-up) Log in for tags link should trigger modal

This patch modifies the "Log in to add tags" link on the OPAC search
results page, adding the class which is used elsewhere in the OPAC
templates for triggering the login modal.

Also: Removed an unnecessary period.

To test, apply the patch and follow the original test plan. Clicking the
"Log in to add tags" link should trigger the login modal. After logging
in you should be returned to the page you were on.

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>