fix(接口测试): 修复新建的接口创建版本时提示有mock数据的缺陷

--bug=1020899 --user=王孝刚 【接口测试】新建接口，选择其他版本的时候，会有复制备注等选项的弹框提示
https://www.tapd.cn/55049933/s/1316211

api-test/backend/src/main/java/io/metersphere/service/MockConfigService.java

@@ -137,6 +137,8 @@ public class MockConfigService {
         }
         if (request.getApiId() != null) {
             criteria.andApiIdEqualTo(request.getApiId());
+        } else {
+            return new MockConfigResponse(null, new ArrayList<>());
         }
         if (request.getProjectId() != null) {
             criteria.andProjectIdEqualTo(request.getProjectId());