The removal has been done with the following command:
find bin/tests/system/ -type f -name "*.db*" -exec sed -i '1,10d; 11{/^$/d}' {} +
The following files have been handled manually, since they already
didn't have the license info, or had it in a slightly different format:
bin/tests/system/ssutoctou/ns1/example.db.in
bin/tests/system/checkzone/zones/crashzone.db
bin/tests/system/checkzone/zones/warn.deprecated.cds-sha1.db
bin/tests/system/checkzone/zones/warn.deprecated.digest-sha1.db
bin/tests/system/checkzone/zones/warn.deprecated.ds-alg.db
bin/tests/system/legacy/ns6/edns512.db.signed
Add randomizens system test which ensures that NS are randomly selected.
The test relies of the fact that `getaddresses_allowed()` logic won't
allow to query more than 3 NS at the top-level. The `example.` zone has
4 NS and the 3 formers are lame. As a result, if the resolved doesn't
randomize the NS selection, it will only quiery the 3 formers, which
won't give an answer, and fails. With randomization enabled, there is a
chance that the resolver queries the fourth NS, and gets the result.
