EventLogging: send esams data directly to vanadium using private iface

bits/event.gif data from esams is currently routed through gadolinium. It was
configured like that because there was no private link between esams and eqiad.
But that's not the case any more, so let's drop it to simplify the setup.

Change-Id: I25adfc05faadbc9d51cfa89b17aac39cdc7e4cba