change security access right and max evt/sec to forward

[lprat]

Hello,

Thank you for your project!
Little contribution:
- modify: to change access to security events to the "network service" account.
- add: max evts/sec forwarding to avoid saturation

Thank,
Regards,
Lionel

[palantirtech]

Thanks for your interest in palantir/windows-event-forwarding, @lprat! 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.