fix(用例管理): 附件转存，错误信息提示

--bug=1038827 --user=王旭 【用例管理】创建用例-上传相同附件，点击转存，提示信息中带异常信息 https://www.tapd.cn/55049933/s/1491787

backend/services/case-management/src/main/java/io/metersphere/functional/controller/FunctionalCaseAttachmentController.java

@@ -140,7 +140,7 @@ public class FunctionalCaseAttachmentController {
             fileId = fileAssociationService.transferAndAssociation(fileAssociationDTO);
             functionalCaseAttachmentService.deleteCaseAttachment(Arrays.asList(request.getFileId()), request.getCaseId(), request.getProjectId());
         } catch (MSException e) {
-            throw new MSException(e);
+            throw new MSException(e.getMessage());
         } catch (Exception e) {
             throw new MSException(Translator.get("file.transfer.failed"));
         }