fix documentation typo

Author: arvidn

include/libtorrent/torrent_info.hpp

@@ -504,7 +504,7 @@ namespace libtorrent
 		// .torrent file. If the specified key cannot be found, it returns NULL.
 		bdecode_node info(char const* key) const;
 
-		// swap the content of this and ``ti```.
+		// swap the content of this and ``ti``.
 		void swap(torrent_info& ti);
 
 		// ``metadata()`` returns a the raw info section of the torrent file. The size