fix 乐器提供方式不存在时，回调报错

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

@@ -865,7 +865,7 @@ public class StudentRegistrationServiceImpl extends BaseServiceImpl<Long, Studen
 			try {
 				contractService.transferMusicGroupCoursesContract(studentRegistration.getUserId(), studentRegistration.getMusicGroupId());
 				// 商品协议(租赁时候有)
-				if (musicOneSubjectClassPlan.getKitGroupPurchaseType().equals(KitGroupPurchaseTypeEnum.LEASE)) {
+				if (musicOneSubjectClassPlan.getKitGroupPurchaseType()!= null && musicOneSubjectClassPlan.getKitGroupPurchaseType().equals(KitGroupPurchaseTypeEnum.LEASE)) {
 					StudentPaymentOrderDetail applyOrderMusical = studentPaymentOrderDetailService.findApplyOrderMusical(studentPaymentOrder.getId());
 					if (applyOrderMusical != null && applyOrderMusical.getGoodsIdList() != null && !applyOrderMusical.getGoodsIdList().equals("")) {
 						contractService.transferGoodsContract(studentPaymentOrder.getUserId(), studentPaymentOrder.getMusicGroupId(),