using dl instead of serverbeach1 for test matrix page download links

[Andre Robatino]

After discussing with smooge and nirik on #fedora-admin, decided to change the
16 Alpha TC1 test matrix pages to use dl.fp.o instead of serverbeach1.fp.o and
alt.fp.o for download links. If no problems are seen, the template pages can be
changed to make it permanent. This would eliminate up to an hour's delay due to
the mirroring from dl to serverbeach1. The latter is still operating as a mirror
and will be available in case there are problems using dl.