fix: guard match live validator scalars

qa/backend/test_match_live_backend_static.php

@@ -129,6 +129,9 @@ $validate = file_get_contents($validatePath);
 foreach ([
     'checkTrimmedTitle',
     'checkTrimmedSourceUrl',
+    "!is_scalar(\$value)",
+    "return '直播标题格式错误';",
+    "return '源地址格式错误';",
     '$value = trim((string) $value);',
 ] as $needle) {
     if (strpos($validate, $needle) === false) {