Fix File.Delete Failure by Waiting for FFmpegProcess to Exit

Core/RenderManager.cs

@@ -601,7 +601,7 @@ namespace ADOFAIRenderer.Core
 
                 if (_activeVideoFFmpeg != null)
                 {
-                    _activeVideoFFmpeg.Kill();
+                    _activeVideoFFmpeg.Kill(16384);
                     _activeVideoFFmpeg = null;
                 }