buffer duration / recount may not be correct for long buffer events

[tzarebczan]

I think there's an issue when you force buffering with throttling and we buffer way too long, we don't properly capture. And sometimes you get:

{"message":"rebufferung duration cannot be larger than duration"}

from:

bitrate: 4930920
device: "web"
duration: 10000
player: "use-p2"
position: 2000
protocol: "stb"
rebuf_count: 1
rebuf_duration: 17750
rel_position: 0
url: "@cryptoinvestsvk#2/Bitcoin-update2#0"
user_id: "1662955"

To reproduce, add slow 3g and watch playback requests.

[tzarebczan]

This was hacked around to send the full duration for now.