embed: error on zero heartbeat-interval, election-timeout
embed: error on zero heartbeat-interval, election-timeout

Signed-off-by: Gyu-Ho Lee <3454051ee3341eb69bdf6fca40899cdad4d86496@gmail.com>

mqliang/etcd,mqliang/etcd,glevand/coreos--etcd,mqliang/etcd,cockroachdb/etcd,dannysauer/etcd,li-ang/etcd,sinsharat/etcd,joshix/etcd,coreos/etcd,ajityagaty/etcd,dannysauer/etcd,lorneli/etcd,rnaveiras/etcd,whuwxl/etcd,cockroachdb/etcd,fanminshi/etcd,heyitsanthony/etcd,bluebreezecf/etcd,bluebreezecf/etcd,lorneli/etcd,etcd-io/etcd,xiang90/etcd,sebrandon1/etcd,gyuho/etcd,glevand/coreos--etcd,sebrandon1/etcd,joshix/etcd,heyitsanthony/etcd,whuwxl/etcd,bdarnell/etcd,ajityagaty/etcd,coreos/etcd,mkumatag/etcd,li-ang/etcd,rnaveiras/etcd,fanminshi/etcd,rnaveiras/etcd,vimalk78/etcd,etcd-io/etcd,mkumatag/etcd,sinsharat/etcd,bdarnell/etcd,ajityagaty/etcd,gyuho/etcd,mkumatag/etcd,vimalk78/etcd,xiang90/etcd,etcd-io/etcd