Uploading subscription buffer increases

[novaksam]

These tweaks help increase the events per second I was able to collect so I wanted to share.

[palantirtech]

Thanks for your interest in palantir/windows-event-forwarding, @novaksam! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.