URL query format is bad

Some torrent files having additional information in _announce_ are processed incorrectly (having `?`).
In example file having _announce_ `http://announce.torrent.ai:2710/v2/announce.php?passkey=596fb54cc069f470c359af14498232323`
is converted to URL http://announce.torrent.ai:2710/v2/announce.php?passkey=596fb54cc069f470c359af1449823b69?info_hash=%f4%53%21%41%a0%a4%3e%54%e3%66%67%4f%3e%ca%27%10%63%db%d3%...

but the **announce.php?** should be **announce.php&**

Start by tracing how the torrent announce URL is processed and how the info_hash query parameter is appended. Reproduce the issue with the announce URL containing passkey=..., then verify that the existing query separator is preserved and the resulting URL uses '&' before info_hash.

Written by the indexing model from the issue text.