functional/tester: update import path

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

functional/tester/failure_case_sigquit_remove.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/coreos/etcd/clientv3"
 	"github.com/coreos/etcd/functional/rpcpb"
+
 	"go.uber.org/zap"
 )