修改subjectvie_score表的索引，group_number字段不再加入索引，换成main_number和main_score

stmms-web/src/main/webapp/sql/stmms_ft.sql

@@ -388,7 +388,7 @@ CREATE TABLE `eb_subjective_score`
     `main_score`   double      NOT NULL COMMENT '大题得分',
     `score`        double      NOT NULL COMMENT '小题得分',
     PRIMARY KEY (`student_id`, `main_number`, `sub_number`),
-    KEY `index1` (`exam_id`, `subject_code`, `group_number`)
+    KEY `index1` (`exam_id`, `subject_code`, `main_number`, `main_score`)
 ) ENGINE = InnoDB
   DEFAULT CHARSET = utf8mb4 COMMENT ='主观题得分明细表';