Tweak NFS repo setup in _support_server to copy all files

`cp -R foo/*` doesn't get all files in `foo/`, it misses hidden
files. This turns out to be a problem with recent anaconda, as
it expects to find a .treeinfo file here. So, let's use rsync.
We could probably do this with cp too but I can't think of the
right arguments right now...

Signed-off-by: Adam Williamson <awilliam@redhat.com>

tests/_support_server.pm

@@ -134,7 +134,8 @@ sub run {
         # mount the ISO there
         assert_script_run "mount /dev/cdrom /mnt/iso";
         # copy the contents of the ISO to the repo share
-        assert_script_run "cp -R /mnt/iso/* /repo", 180;
+        assert_script_run "dnf -y install rsync", 180;
+        assert_script_run "rsync -av /mnt/iso/ /repo", 180;
         # put the updates image in the NFS repo (for testing this update
         # image delivery method)
         assert_script_run "curl -o /repo/images/updates.img https://fedorapeople.org/groups/qa/updates/updates-openqa.img";