Revert "Labs: switch dumps to the new server"

This reverts commit 502528c8099382ec5e64531d2203533c77470816.

Reverting cause labstore1003 is not yet ready to accept mount requests
and labs machines would end having a mount process stuck at trying to
mount /dumps. Puppet tries to ensure that mountpoint mounted and hence
gets stuck as well

Conflicts:
	modules/dataset/manifests/cron/rsync/labs.pp

Change-Id: I5c64b7988e153a75bf00fc0ecd5e15ca6862fb59