Bug 12295: fix Javascript error when merging authorities

Bug 12295: fix Javascript error when merging authorities

Attempting to merge authorities results in the following error:
Uncaught SyntaxError: Unexpected token u authorities-home.pl:284
    showMergingInProgress authorities-home.pl:284
    (anonymous function) authorities-home.pl:297
    o jquery.js:2
    p.fireWith jquery.js:2
    e.extend.ready jquery.js:2
    c.addEventListener.B

This was the result of the upgrade of jquery-cookie by the patch
for bug 11369; newer versions of jquery-cookie changed the return of
$.cookie('foo') from null to undefined when the cookie is not present.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
No test plan, no errors.

Test
1. search some authorities
2. click merge, on browser dev console pops reported error message
'Unexpected token u authorities-home.pl...'
No way to marge auths
3. with pach applied, merging works again

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 1857c444cc6666331eae34e9a99fa1eaa3f1c760)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>