Bug 22881: Trying to clear search history via the navbar X doesn't clear any searches

Bug 22881: Trying to clear search history via the navbar X doesn't clear any searches

This patch undoes a mistake introduced in my patch for Bug 21479. A
"preventDefault()" was added to the search history clear button by
mistake. The "confirmDelete" function only works if the default action
of the link is allowed to complete.

To test you must have the EnableOpacSearchHistory system preference
enabled. Apply the patch and log into the OPAC as a patron who has a
search history.

Click the "X" link in the header next to the "Search history" link.
Confirm that you want to clear your search history. The page should
refresh. Navigate to your account -> Your search history to confirm that
your search history has been cleared.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>