fix: Form save error

--bug=1068056@tapd-34675357 --user=宋昌昌 【回款计划&回款记录】导出显示字段时，发现数据源单选(合同)未导出 https://www.tapd.cn/34675357/s/1892403

Author: song-cc-rock

backend/crm/src/main/java/cn/cordys/crm/system/service/ModuleFormService.java

@@ -299,17 +299,18 @@ private void resetSerial(List<ModuleField> oldFields, List<BaseField> saveFields
      */
     private void saveFields(List<BaseField> saveFields, String saveFormId, String currentUserId) {
         // 剔除引用字段&&并保留到数据源引用字段
-        List<String> showFields = saveFields.stream().filter(f -> f instanceof DatasourceField sourceField && CollectionUtils.isNotEmpty(sourceField.getShowFields()))
+		List<BaseField> fieldToSave = new ArrayList<>(saveFields);
+        List<String> showFields = fieldToSave.stream().filter(f -> f instanceof DatasourceField sourceField && CollectionUtils.isNotEmpty(sourceField.getShowFields()))
                 .flatMap(sf -> ((DatasourceField) sf).getShowFields().stream()).distinct().toList();
-        List<BaseField> refFields = saveFields.stream().filter(f -> showFields.contains(f.getId()))
+        List<BaseField> refFields = fieldToSave.stream().filter(f -> showFields.contains(f.getId()) && StringUtils.isNotEmpty(f.getResourceFieldId()))
                 .collect(Collectors.toMap(BaseField::getId, Function.identity(), (a, b) -> a)).values().stream()
                 .toList();
-        saveFields.removeAll(refFields);
+		fieldToSave.removeAll(refFields);
 
         List<ModuleField> addFields = new ArrayList<>();
         List<ModuleFieldBlob> addFieldBlobs = new ArrayList<>();
         AtomicLong pos = new AtomicLong(1);
-        saveFields.forEach(field -> {
+		fieldToSave.forEach(field -> {
             ModuleField moduleField = new ModuleField();
             moduleField.setId(field.getId());
             moduleField.setFormId(saveFormId);