sql: bump rsg func exec timeout to 10s
sql: bump rsg func exec timeout to 10s

5s is maybe too conservative with so many rsg goroutines running in parallel. This will hopefully fix the recent RSG test failures.
veteranlu/cockroach,veteranlu/cockroach,maxlang/cockroach,maxlang/cockroach,vaibhavarora/cockroach,maxlang/cockroach,maxlang/cockroach,veteranlu/cockroach,maxlang/cockroach,maxlang/cockroach,veteranlu/cockroach,glycerine/cockroach,veteranlu/cockroach,paperstreet/cockroach,glycerine/cockroach,paperstreet/cockroach,paperstreet/cockroach,petermattis/cockroach,petermattis/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,maxlang/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,glycerine/cockroach,vaibhavarora/cockroach,petermattis/cockroach,glycerine/cockroach,glycerine/cockroach,paperstreet/cockroach,petermattis/cockroach,vaibhavarora/cockroach,glycerine/cockroach,petermattis/cockroach,vaibhavarora/cockroach,maxlang/cockroach,petermattis/cockroach,glycerine/cockroach,veteranlu/cockroach,glycerine/cockroach,petermattis/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,petermattis/cockroach,veteranlu/cockroach,paperstreet/cockroach,paperstreet/cockroach