Bugfix: OcclusionGroups - eagerly clean up occlusion group when teleporting - consolidated occlusion-group leaving logic Caught the bastard - due to over-time nature of subscription updating, there was a window in which the player could teleport and disconnect, leading to a leak of occlusion group and a null participant. Tests: on client, teleport2marker;kill, then separatelly disconnect; then on server run OcclusionValidateGroupson - all's gud