not all torrents have announce

ox/torrent/__init__.py

@@ -55,6 +55,7 @@ def get_torrent_info(data=None, file=None):
             tinfo[key] = metainfo[key]
     tinfo['size'] = file_length
     tinfo['hash'] = sha1(bencode(info)).hexdigest()
+    if 'announce' in metainfo:
         tinfo['announce'] = metainfo['announce']
     if file:
         tinfo['timestamp'] = os.stat(file).st_ctime