Title: #5303: ipatests: fix TestTrust::test_subordinate_suffix
The test test_subordinate_suffix is failing when configuring the DNS
for the trust, because the dnsforwardzone already exists. It was
configured during the previous test for nonposix trust.
At the end of the tests for nonposix trust, unconfigure the DNS
and the trust before calling the subordinate_suffix test, and add
a test cleaning up subordinate_suffix test.
To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/5303/head:pr5303
git checkout pr5303