py3: Remove comparison >=2 of debnug log level
    
    We have only one debug log level and it causes issues with py3.
    ...
      File "/usr/lib/python3.5/site-packages/ipaserver/rpcserver.py", line 490, in marshal
        response, version, pretty_print=self.api.env.debug >= 2
    TypeError: unorderable types: str() >= int()
    
    https://pagure.io/freeipa/issue/4985
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>