silence a spurious dnssec-keygen warning in the dnssec system test

the occluded-key test creates both a KEY and a DNSKEY. the second
call to dnssec-keygen calls dns_dnssec_findmatchingkeys(), which causes
a spurious warning to be printed when it sees the type KEY record.
this should be fixed in dnssec.c, but the meantime this change silences
the warning by reversing the order in which the keys are created.
41 jobs for !1238 with each-silence-warning in 19 minutes and 13 seconds (queued for 4 seconds)
detached
Status Job ID Name Coverage
  Precheck
passed 🐞:sid:amd64 #165156
amd64 linux

00:00:36

passed misc:sid:amd64 #165155
amd64 linux

00:00:18

 
  Build
passed asan:sid:amd64 #165167
amd64 linux

00:04:40

passed clang:stretch:amd64 #165168
amd64 linux

00:01:46

passed clang:stretch:i386 #165169
i386 linux

00:01:53

passed docs:sid:amd64 #165157
amd64 linux

00:00:57

passed gcc:bionic:amd64 #165166
amd64 linux

00:01:06

passed gcc:centos6:amd64 #165158
amd64 linux

00:02:18

passed gcc:centos7:amd64 #165159
amd64 linux

00:02:36

passed gcc:fedora29:amd64 #165164
amd64 linux

00:02:36

passed gcc:jessie:amd64 #165160
amd64 linux

00:01:37

passed gcc:sid:amd64 #165162
amd64 linux

00:01:17

passed gcc:sid:i386 #165163
i386 linux

00:03:06

passed gcc:stretch:amd64 #165161
amd64 linux

00:01:49

passed gcc:xenial:amd64 #165165
amd64 linux

00:01:37

passed pkcs11:sid:amd64 #165170
amd64 linux

00:01:48

 
  Test
passed install:gcc:sid:amd64 #165179
amd64 linux

00:02:19

passed system:asan:sid:amd64 #165190
amd64 linux

00:08:29

passed system:gcc:bionic:amd64 #165188
amd64 linux

00:07:05

passed system:gcc:centos6:amd64 #165171
amd64 linux

00:06:08

passed system:gcc:centos7:amd64 #165173
amd64 linux

00:07:05

passed system:gcc:fedora29:amd64 #165184
amd64 linux

00:07:04

passed system:gcc:jessie:amd64 #165175
amd64 linux

00:06:52

passed system:gcc:sid:amd64 #165180
amd64 linux

00:07:13

passed system:gcc:sid:i386 #165182
i386 linux

00:06:31

passed system:gcc:stretch:amd64 #165195
linux amd64

00:06:24

passed system:gcc:xenial:amd64 #165186
amd64 linux

00:06:09

passed system:pkcs11:sid:amd64 #165193
amd64 linux

00:06:25

passed unit:asan:sid:amd64 #165191
amd64 linux

00:00:52

passed unit:clang:stretch:amd64 #165192
amd64 linux

00:00:42

passed unit:gcc:bionic:amd64 #165189
amd64 linux

00:00:43

passed unit:gcc:centos6:amd64 #165172
amd64 linux

00:00:57

passed unit:gcc:centos7:amd64 #165174
amd64 linux

00:00:57

passed unit:gcc:fedora29:amd64 #165185
amd64 linux

00:00:52

passed unit:gcc:jessie:amd64 #165176
amd64 linux

00:00:31

passed unit:gcc:sid:amd64 #165181
amd64 linux

00:00:55

passed unit:gcc:sid:i386 #165183
i386 linux

00:00:52

passed unit:gcc:stretch:amd64 #165178
amd64 linux

00:00:58

passed unit:gcc:xenial:amd64 #165187
amd64 linux

00:00:47

passed unit:pkcs11:sid:amd64 #165194
amd64 linux

00:00:42

failed system:gcc:stretch:amd64 #165177
amd64 linux

00:07:22