fix(测试跟踪): 测试计划关联功能用例页面，模块数据成显示上一次切换项目后的数据

--bug=1025631 --user=陈建星 【测试跟踪】测试计划-切换项目关联项目下所有功能用例-再次关联默认项目模块树为空 https://www.tapd.cn/55049933/s/1364847

test-track/frontend/src/business/plan/view/comonents/functional/FunctionalRelevance.vue

@@ -216,6 +216,9 @@ export default {
   },
   watch: {
     projectId(val) {
+      if (!this.projectId) {
+        return;
+      }
       this.setConditionModuleIdParam();
       this.page.condition.projectId = this.projectId;
       this.page.condition.versionId = null;
@@ -234,9 +237,6 @@ export default {
         this.$refs.table.clear();
         this.$refs.table.clearSort();
       }
-      if (this.projectId) {
-        this.getProjectNode(this.projectId);
-      }
     },
     setProject(projectId) {
       this.projectId = projectId;
@@ -300,6 +300,7 @@ export default {
     close() {
       this.selectNodeIds = [];
       this.selectNodeNames = [];
+      this.projectId = '';
       this.$refs.table.clear();
     },
     getProjectNode(projectId, condition) {