无摄像头检测器，则不检测

src/features/OnlineExam/Examing/ExamingHome.vue

@@ -175,6 +175,7 @@ export default {
     if (typeof nodeRequire != "undefined") {
       try {
         var fs = window.nodeRequire("fs");
+        if (!fs.existsSync("multiCamera.exe")) return;
 
         window.nodeRequire("node-cmd").get("multiCamera.exe", () => {
           let CameraInfo = fs.readFileSync("CameraInfo.txt", "utf-8");