修正变更校区关系更新bug

ie-system/src/main/java/com/ruoyi/dz/service/impl/DzCardsServiceImpl.java

@@ -464,7 +464,7 @@ public class DzCardsServiceImpl implements IDzCardsService
             dzCardsMapper.updateDzCards(dzCards);
 
             SysUser u = userMap.get(c.getCardId());
-            if(null == u) {
+            if(null != u) {
                 LearnStudent upStudent = new LearnStudent();
                 upStudent.setStudentId(u.getUserId());
                 upStudent.setClassId(campusClassId);