bean: encode(String) in URLEncoder has been deprecated

Change-Id: Ife3eaaaad199e79aeb6886a146324ffb145c7bc3
Reviewed-on: https://gerrit.libreoffice.org/11476
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>