Fix warning with datepicker.js

Change-Id: I4c978f0fbcac20e706bd93b19cfd6cd9bedaf6db
Merge commit 'refs/changes/78/2278/1' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Fix warning with datepicker.js

Change-Id: Ib753844d45f8fa8915fb185412090331008a8918
This is Tuleap 6.12.99.35

Change-Id: Ic52629d9c07a96fdcbc720196ccd3a70d027ae0d