修复B站每日签到没有周任务时的异常

src/main/java/com/yutou/qqbot/bilibili/AppUserTask.java

@@ -18,6 +18,13 @@ public class AppUserTask {
     private long weekGroup;
     private DayTask dayTask;
 
+    public List<WeekTask> getWeekTask() {
+        if(weekTask == null){
+            weekTask=new ArrayList<>();
+        }
+        return weekTask;
+    }
+
     public static String toMessageFormat(AppUserTask oldTask, AppUserTask newTask) {
         StringBuilder sb = new StringBuilder();
         sb.append("当前电池数量:").append(String.format("%.2f → %.2f",