Throw download as failed for invalid magnet links

(cherry picked from commit 091449d9bff9023ca27a85cc1048296f7d5ea37b)

Closes #9625
Fixes #9125

src/NzbDrone.Core/Download/TorrentClientBase.cs

@@ -223,9 +223,7 @@ namespace NzbDrone.Core.Download
             }
             catch (FormatException ex)
             {
-                _logger.Error(ex, "Failed to parse magnetlink for movie '{0}': '{1}'", remoteMovie.Release.Title, magnetUrl);
-
-                return null;
+                throw new ReleaseDownloadException(remoteMovie.Release, "Failed to parse magnetlink for episode '{0}': '{1}'", ex, remoteMovie.Release.Title, magnetUrl);
             }
 
             if (hash != null)