Ignore unused loop counter.

mods/track_players/init.lua

@@ -3,7 +3,7 @@ local fifo_path "/tmp/mt_players_fifo"
 
 function players_data()
     ps = {}
-    for i, player in ipairs(minetest.get_connected_players()) do
+    for _, player in ipairs(minetest.get_connected_players()) do
         local pos = player:getpos()
         local name = player:get_player_name()
         local data = {