Small OpenGraph fix

Fixed incorrect URL

app/index.html

@@ -30,8 +30,8 @@
   <meta name="theme-color" content="#497495">
 
   <meta property="og:title" content="Telegram Web">
-  <meta property="og:url" content="https://web.telegram.org/webogram/">
-  <meta property="og:image" content="https://web.telegram.org/webogram/img/logo_share.png">
+  <meta property="og:url" content="https://web.telegram.org/">
+  <meta property="og:image" content="https://web.telegram.org/img/logo_share.png">
   <meta property="og:site_name" content="Telegram Web">
   <meta property="og:description" content="Welcome to the Web application of Telegram messenger. See https://github.com/zhukov/webogram for more info.">