Fix possible hud vector error

hud.lua

@@ -5,7 +5,9 @@ areas.hud = {}
 minetest.register_globalstep(function(dtime)
 	for _, player in pairs(minetest.get_connected_players()) do
 		local name = player:get_player_name()
-		local pos = vector.round(player:getpos())
+		local pos = player:getpos()
+		if pos then
+			pos = vector.round(pos)
 			local owners = areas:getNodeOwners(pos)
 			local ownerString = table.concat(owners, ", ")
 			if not areas.hud[name] then
@@ -30,6 +32,7 @@ minetest.register_globalstep(function(dtime)
 				areas.hud[name].oldOwners = ownerString
 			end
 		end
+	end
 end)
 
 minetest.register_on_leaveplayer(function(player)