1、服务器列表增加点击后自动跳转首页

2、首页增加切换服务器功能

app/src/main/java/com/example/myapplication/data/ServerDao.java

@@ -22,4 +22,10 @@ public interface ServerDao {
     void deleteLegacySampleServers();
     @Query("DELETE FROM servers WHERE id = :serverId")
     void deleteServer(String serverId);
-}
+
+    @Query("UPDATE servers SET isSelected = 0")
+    void clearAllSelected();
+
+    @Query("UPDATE servers SET isSelected = 1 WHERE id = :serverId")
+    void setSelected(String serverId);
+}