Make Lua code area and error label use monospaced font (#541)

mesecons_luacontroller/init.lua

@@ -664,6 +664,7 @@ local function reset_formspec(meta, code, errmsg)
 	code = minetest.formspec_escape(code or "")
 	errmsg = minetest.formspec_escape(tostring(errmsg or ""))
 	meta:set_string("formspec", "size[12,10]"
+		.."style_type[label,textarea;font=mono]"
 		.."background[-0.2,-0.25;12.4,10.75;jeija_luac_background.png]"
 		.."label[0.1,8.3;"..errmsg.."]"
 		.."textarea[0.2,0.2;12.2,9.5;code;;"..code.."]"