update 缴费金额为0时，报名、续费不能建多期

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

@@ -206,13 +206,13 @@ public class MusicGroupPaymentCalenderServiceImpl extends BaseServiceImpl<Long,
 			musicGroupPaymentCalenderCourseSettingsList = new ArrayList<>();
 		}
 
-		// 缴费金额为0时，报名、续费不能建多期
+		// 必须课程缴费金额为0时，报名、续费不能建多期
 		if(paymentType == MUSIC_APPLY || paymentType == MUSIC_RENEW){
 			BigDecimal noOptionalCoursePrice = musicGroupPaymentCalenderCourseSettingsList.stream()
 					.filter(e -> !e.getIsStudentOptional()).map(MusicGroupPaymentCalenderCourseSettings::getCourseCurrentPrice)
 					.reduce(BigDecimal.ZERO, BigDecimal::add);
 			if(noOptionalCoursePrice.compareTo(BigDecimal.ZERO) <= 0 && musicGroupPaymentDateRangeList.size() > 1){
-				throw new BizException("缴费金额为0时不支持多周期缴费");
+				throw new BizException("必选课程缴费金额为0时不支持多周期缴费");
 			}
 		}