Fix p2 tests to not use http://download.eclipse.org

Fixes many warnings printed during running p2 tests about unsecure p2
site location.

Change-Id: I5488712fd23044a9af992c8751a687f7c42e3c43
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
Reviewed-on: https://git.eclipse.org/r/c/equinox/rt.equinox.p2/+/186419
Tested-by: Equinox Bot <equinox-bot@eclipse.org>
20 files changed