Fixed incorrect return code assert

The assert checked that the returncode of the replica uninstallation is zero
where in fact the uninstallation was expected to fail with the certain error
message

Reviewed-By: Martin Basti <mbasti@redhat.com>

ipatests/test_integration/test_replica_promotion.py

@@ -345,7 +345,7 @@ class TestProhibitReplicaUninstallation(IntegrationTest):
         result = self.replicas[0].run_command(['ipa-server-install',
                                                '--uninstall', '-U'],
                                               raiseonerr=False)
-        assert(result.returncode == 0), ("The replica was removed without "
+        assert(result.returncode > 0), ("The replica was removed without "
                                          "'--ignore-topology-disconnect' option")
         assert("Uninstallation leads to disconnected topology"
                in result.stdout_text), ("Expected error message was not found")