Fix thumbnail error

Tesses.YouTubeDownloader/src/YouTubeDownloader.tcross

@@ -908,7 +908,7 @@ class TYTD.Downloader {
 					this.Mutex.Lock();
 					var db = this.OpenDB();
 					var res = Sqlite.Exec(db, "SELECT * FROM subscriptions;");
-					Sqlite.Close(res);
+					Sqlite.Close(db);
 					//Sqlite.Exec(db,"CREATE TABLE IF NOT EXISTS subscriptions (id INTEGER PRIMARY KEY AUTOINCREMENT, channelId TEXT UNIQUE ON CONFLICT REPLACE, bell TEXT);");
 				
 					this.Mutex.Unlock();