remove re-signing race when testing dnskey-sig-validity

(cherry picked from commit 7288d321)
7 jobs for 145-dnskey-sigvalidity-v9_11 in 5 minutes and 54 seconds (queued for 13 seconds)
Status Job ID Name Coverage
  Precheck
passed #21879
amd64 docker linux
precheck:debian:sid:amd64

00:00:11

 
  Build
passed #21880
amd64 docker linux
build:debian:sid:amd64

00:01:22

passed #21881
i386 docker linux
build:debian:sid:i386

00:01:24

 
  Test
passed #21884
amd64 docker linux
systemtest:debian:sid:amd64

00:04:08

passed #21885
i386 docker linux
systemtest:debian:sid:i386

00:04:16

passed #21882
amd64 docker linux
unittest:debian:sid:amd64

00:00:51

passed #21883
i386 docker linux
unittest:debian:sid:i386

00:00:48