src/audio/audioplayer: do not use open() on QNetworkReply

For obscure and unknown reasons, calling open() on a QNetworkReply
sometimes resets the buffer in a way that only allows retrieving the
data under conditions out of our control, resulting in an empty file
being written. It doesn't appear to be necessary anyway so omitting it
works just fine.

src/audio/audioplayer.cpp

@@ -146,12 +146,6 @@ AudioPlayerReply *AudioPlayer::playAudio(QString url, QString hash)
                 goto cleanup;
             }
 
-            if (!reply->open(QIODevice::ReadOnly))
-            {
-                qDebug() << "Could not open audio reply";
-                goto cleanup;
-            }
-
             /* Put the audio in a new temp file */
             file = new QTemporaryFile;
             if (!file->open())