fix snapshot interval bug

src/features/OnlineExam/Examing/ExamingHome.vue

@@ -84,7 +84,7 @@ export default {
         this.toggleSnapNow(); // 开启抓拍才在进入考试时抓拍一张
       }, 1 * 1000); // 5秒钟后抓拍
 
-      const snapshotInterval = this.$http.get(
+      const snapshotInterval = await this.$http.get(
         "/api/ecs_exam_work/exam/examOrgProperty/" +
           this.$route.params.examId +
           `/SNAPSHOT_INTERVAL`