优化成绩查询页面中的如果“是否缺考”字段位null时，则在成绩查询页面也判断它为缺考

stmms-web/src/main/webapp/WEB-INF/views/modules/exam/scoreList.jsp

@@ -118,7 +118,7 @@
 				<td>${student.subjectiveScoreString}</td>
 				<td>${student.totalScoreString}</td>
 				<td>
-					<c:if test="${student.absent == true}">
+					<c:if test="${student.absent == true || student.absent == null}">
 						缺考
 					</c:if>
 				</td>