fix：小程序添加流程状态变更

cjl

2023-11-07 a3b34f9f092e1aeacfe6bd4c9e80b7464dcd5912

 screen-manage/src/main/java/com/moral/api/util/CompareFieldUtils.java

@@ -70,7 +70,7 @@
                else
                    result.setNewData(newDataObj.toString());

                if(oldDataObj==null)
                if(oldDataObj==null||oldDataObj.equals(""))
                    result.setOldData("null");
                else
                    result.setOldData(oldDataObj.toString());