fix(测试跟踪): 缺陷管理自定义字段筛选无效

--bug=1020601 --user=宋昌昌 【测试跟踪】github#20399，缺陷字段筛选无效 https://www.tapd.cn/55049933/s/1311314

test-track/frontend/src/business/issue/IssueList.vue

@@ -350,10 +350,7 @@ export default {
     this.editParam();
   },
   methods: {
-    generateColumnKey(field){
-      let columnKey = generateColumnKey(field);
-      return "custom_" + columnKey.substr(columnKey.indexOf("-") + 1);
-    },
+    generateColumnKey,
     hasPermission,
     tableDoLayout() {
       if (this.$refs.table) this.$refs.table.doLayout();