Don't reset TKO state for inactive connections
Don't reset TKO state for inactive connections

Summary: Right now TKO state is coupled with connection resets. e.g. if our TKO probe timer is 70 seconds and we reset connections at 30, we'd actually reset TKOs as soon as TKO probes reached 30 second intervals, which we don't want. With global TKO, we only keep one connection open to a down destination, and we don't really ever want to reset that until the destination either goes unTKO or is removed.

Test Plan: fbmake runtests

Reviewed By: pavlo@fb.com

Subscribers: sameen, andrii, gunjan

FB internal diff: D1422691

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