[mesecons_commandblock] fix warnings

mods/ITEMS/REDSTONE/mesecons_commandblock/init.lua

@@ -72,7 +72,7 @@ end
 local function check_commands(commands, player_name)
 	for _, command in pairs(commands:split("\n")) do
 		local pos = command:find(" ")
-		local cmd, param = command, ""
+		local cmd = command
 		if pos then
 			cmd = command:sub(1, pos - 1)
 		end