fix:export6

Modules/Camera/Http/Controllers/Api/CameraApiController.php

@@ -4495,7 +4495,7 @@ class CameraApiController extends BaseController
                 if ($gao   > 0) $level_total .= '高风险'.$gao."项\n";
                 if ($zhong > 0) $level_total .= '中风险'.$zhong."项\n";
                 if ($di    > 0) $level_total .= '低风险'.$di."项\n";
-                $level_total = substr($level_total, 0, -2);
+                $level_total = mb_substr($level_total, 0, mb_strlen($level_total) - 1);
 
                 $wwdw_num = count($wwdw);
                 $sgdd_num = count($sgdd);