Revert "HGTP-mesh bug: the mesh download requests were going to the departing sims for a little while. This was also true for local TPs. BUt for local TPs the assets are on the same server, so it doesn't matter. For HGTPs, it matters. This potential fix moves sending the initial data to later, after the client has completed the movement into the region. Fingers crossed that it doesn't mess other things up!"

This reverts commit f32a21d96707f87ecbdaf42c0059f8494a119d31.