fix：考级乐理忽略免考

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

@@ -120,6 +120,10 @@ public class DegreeRegistrationServiceImpl extends BaseServiceImpl<Integer, Degr
 
         List<String> courseInfos = new ArrayList<>();
 
+        if("免考".equals(degreeRegistration.getTheoryLevel())){
+            degreeRegistration.setTheoryLevel(null);
+        }
+
         if(StringUtils.isNotBlank(degreeRegistration.getTheoryLevel())){
             degreeRegistration.setOrderNo(orderNo);
             BigDecimal theoryMoney = BigDecimal.ZERO;