The current code assumes every openqa test will have an entry
in TESTSUITES and breaks if it doesn't. All tests *should* have
entries, but it's susceptible to going wrong (as the tests
are in a different git repo so we have to sync the commits
carefully) and it is at least possible we might add tests to
openQA that don't match anything in the matrices, at least right
away. So instead of blowing up the report process with a
KeyError if the testsuite isn't there, just log a warning and
continue.

Set things up so there's an openQA test without a
TESTSUITES entry, run a report, and check that instead of
crashing, the reporter logs a warning and continues.