Multiplayer: When updating remote player tile ensures that it's free

Source/multi.cpp

@@ -641,7 +641,7 @@ void multi_process_network_packets()
 			player._pBaseDex = pkt->bdex;
 			if (!cond && player.plractive && player._pHitPoints != 0) {
 				if (player.isOnActiveLevel() && !player._pLvlChanging) {
-					if (player.position.tile.WalkingDistance(syncPosition) > 3 && dPlayer[pkt->px][pkt->py] == 0) {
+					if (player.position.tile.WalkingDistance(syncPosition) > 3 && PosOkPlayer(player, syncPosition)) {
 						// got out of sync, clear the tiles around where we last thought the player was located
 						FixPlrWalkTags(player);