Fix regression: Handle unicode where str is expected

Regression caused by 947ac4bc1f when
trying to fix a similar issue for clients running Python 3. However,
that fix broke Python 2 clients.

Issue: https://pagure.io/freeipa/issue/7626

Signed-off-by: Armando Neto <abiagion@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>

ipaclient/remote_plugins/schema.py

@@ -608,7 +608,7 @@ def get_package(server_info, client):
             s = topic['topic_topic']
             if isinstance(s, bytes):
                 s = s.decode('utf-8')
-            module.topic = s.partition('/')[0]
+            module.topic = str(s).partition('/')[0]
         else:
             module.topic = None