Fixes bug with manual VoiceNext disconnection.
Created by: Neuheit
Summary
Similar to #544, this fixes a bug with VoiceNext that does not allow it to reconnect after being manually disconnected.
Details
The changes made are very similar to #544, but I additionally included a dispose check inside PreparePacket if there was still audio playing. This prevents a null ref from being thrown if both PreparePacket and Dispose are being performed concurrently.