install-autotest-server.sh: relocate apache-web.conf to new $ATHOME

We need to update the DocumentRoot in apache-web-conf to point to the
new $ATHOME.

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
Merge pull request #765 from rbbratta/install_fix1

install-autotest-server.sh: relocate apache-web-conf to new $ATHOME