fix 班级人数

mec-biz/src/main/java/com/ym/mec/biz/service/impl/MusicGroupServiceImpl.java

@@ -289,6 +289,7 @@ public class MusicGroupServiceImpl extends BaseServiceImpl<String, MusicGroup> i
                     studentRegistration.setMusicGroupId(musicGroupId);
                     studentRegistration.setSubjectId(e.getSubjectId());
                     studentRegistration.setActualSubjectId(e.getSubjectId());
+                    studentRegistration.setTemporaryCourseFee(null);
                 }
                 studentRegistrationList.addAll(musicGroupStudentRegistrationList);