siege: use debian mirror

Fixes #29832.
Hide zookeeper java process from the Dock

setting `SERVER_JVMFLAGS` to `-Dapple.awt.UIElement=true` will prevent the java process from showing up in the Dock.

Closes #29835.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
jack 0.124.1

The jack download url was broken due to a site hack - updated to the url
currently shown on the homepage and added the newly required dependency
for 0.124.1 (berkeley-db).

Closes #29800.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>