kv: add a comment about wanting cancellable contexts in TxnCoordSender
kv: add a comment about wanting cancellable contexts in TxnCoordSender

maxlang/cockroach,glycerine/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,maxlang/cockroach,paperstreet/cockroach,maxlang/cockroach,petermattis/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,glycerine/cockroach,paperstreet/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,petermattis/cockroach,glycerine/cockroach,paperstreet/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,veteranlu/cockroach,paperstreet/cockroach,maxlang/cockroach,vaibhavarora/cockroach,vaibhavarora/cockroach,glycerine/cockroach,glycerine/cockroach,maxlang/cockroach,veteranlu/cockroach,veteranlu/cockroach,petermattis/cockroach,maxlang/cockroach,paperstreet/cockroach,maxlang/cockroach,veteranlu/cockroach,petermattis/cockroach,maxlang/cockroach,petermattis/cockroach,glycerine/cockroach,vaibhavarora/cockroach,petermattis/cockroach,vaibhavarora/cockroach,glycerine/cockroach,veteranlu/cockroach,petermattis/cockroach,veteranlu/cockroach,petermattis/cockroach,glycerine/cockroach