fix: 修复is_new未定义

include/global.func.php

@@ -30,7 +30,7 @@ function gameerrorhandler($code, $msg, $file, $line){
 function gexit($message = '',$file = '', $line = 0) {
 	global $charset,$title,$extrahead,$allowcsscache,$errorinfo;
 	global $gameversion,$cuser,$cpass;
-	if ($_GET['is_new']) {
+	if (isset($_GET['is_new'])) {
 		echo json_encode(array(
 			"error" => $message,
 		));

index.php

@@ -57,7 +57,7 @@ if(!empty($roomact))
 }
 else 
 {
-  if ($_GET['is_new']) {
+  if (isset($_GET['is_new'])) {
     echo json_encode(array(
       // 当前回合数
       "num" => $gamenum,

valid.php

@@ -284,7 +284,7 @@ if($mode == 'enter') {
 	save_gameinfo();
 	
 
-	if ($_GET['is_new']) {
+	if (isset($_GET['is_new'])) {
 		echo json_encode(array(
 			"page" => "validOver",
 			"nick" => $nickinfo,
@@ -325,7 +325,7 @@ if($mode == 'enter') {
 	$iconarray = get_iconlist($icon);
 	$utlist = get_utitlelist();
 	$select_icon = $icon;
-	if ($_GET['is_new']) {
+	if (isset($_GET['is_new'])) {
 		// 获取可选称号
 		$nickList = array_map(function($val) use ($titles_list) {
 			return array(