fix:计算课酬时，学生人数从课程上取

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

@@ -1208,7 +1208,7 @@ public class CourseScheduleTeacherSalaryServiceImpl extends BaseServiceImpl<Long
                 if(studentNum>5){
                     studentNum=5;
                 }
-                salary = JSON.parseObject(teacherDefaultMusicGroupSalary.getSalaryRuleJson()).getBigDecimal(studentNum.toString());
+                salary = JSON.parseObject(teacherDefaultMusicGroupSalary.getSalaryRuleJson()).getBigDecimal(studentNum+"");
             }
 
             if (courseSchedule.getType().equals(CourseSchedule.CourseScheduleType.MUSIC_NETWORK)) {