py3: test_location_plugin: fix iteration over changed dict

In py3 dict.items() doesn't return list so we must create a list to
avoid changing dictionary over iteration.

https://pagure.io/freeipa/issue/4985

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

.travis.yml

@@ -67,6 +67,7 @@ env:
           TESTS_TO_RUN="test_cmdline
                 test_ipalib
                 test_pkcs10
+                test_xmlrpc/test_location_plugin.py
                 test_xmlrpc/test_nesting.py
                 test_xmlrpc/test_netgroup_plugin.py
                 test_xmlrpc/test_old_permission_plugin.py
@@ -112,7 +113,6 @@ env:
             # test_ipaserver/test_version_comparison.py
             ## test_ipaserver
             ## test_xmlrpc/test_[l-z]*.py
-            # test_xmlrpc/test_location_plugin.py
             # test_xmlrpc/test_range_plugin.py
             # test_xmlrpc/test_trust_plugin.py
             # test_xmlrpc/test_vault_plugin.py

ipatests/test_xmlrpc/tracker/server_plugin.py

@@ -124,7 +124,7 @@ class ServerTracker(Tracker):
         result = command()
         self.attrs.update(updates)
         self.attrs.update(expected_updates)
-        for key, value in self.attrs.items():
+        for key, value in list(self.attrs.items()):
             if value is None:
                 del self.attrs[key]