use guard values for testing unixtime serial

(cherry picked from commit abe41ba0)
17 jobs for 424-nsupdate-tests-fail-intermittently-v9_11 in 15 minutes and 51 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #30450
amd64 docker linux

00:00:12

 
  Build
passed build:centos:centos6:amd64 #30451
amd64 docker linux

00:02:46

passed build:centos:centos7:amd64 #30452
amd64 docker linux

00:02:56

passed build:debian:sid:amd64 #30453
amd64 docker linux

00:01:56

passed build:debian:sid:i386 #30632
linux docker i386

00:01:25

passed build:debian:sid:i386 #30454
i386 docker linux

00:02:01

 
  Test
passed systemtest:centos:centos6:amd64 #30459
amd64 docker linux

00:05:00

passed systemtest:centos:centos7:amd64 #30460
amd64 docker linux

00:05:02

passed systemtest:debian:sid:amd64 #30461
amd64 docker linux

00:04:38

passed systemtest:debian:sid:i386 #30660
linux docker i386

00:04:39

passed unittest:centos:centos6:amd64 #30455
amd64 docker linux

00:00:58

passed unittest:centos:centos7:amd64 #30456
amd64 docker linux

00:00:59

passed unittest:debian:sid:amd64 #30457
amd64 docker linux

00:00:57

passed unittest:debian:sid:i386 #30458
i386 docker linux

00:00:53

failed systemtest:debian:sid:i386 #30633
i386 docker linux

00:05:58

failed systemtest:debian:sid:i386 #30631
linux docker i386

00:00:00

failed systemtest:debian:sid:i386 #30462
i386 docker linux

00:05:23