Add licencing info to js/sprintf.js from https://github.com/kvz/phpjs/blob/master/LICENSE.txt

Signed-off-by: Atul Pratap Singh <atulpratapsingh05@gmail.com>
Merge branch 'master' of github.com:phpmyadmin/phpmyadmin
Merge branch 'master' of github.com:phpmyadmin/phpmyadmin