Anaconda hang with GDBus.Error ...UnknownMethod for PowerPC F26 ks install

for QA ks tests (like QA:Testcase_kickstart_firewall_configured or QA:Testcase_kickstart_firewall_disabled ...)


The problem started with f26 compose 20170403 (no failure with 20170331)
The same problem is still alive with 20170404

===
anaconda 26.21.1-1 for Fedora 26 (pre-release) started.
 * installation log files are stored in /tmp during the installation
 * shell is available on TTY2
 * when reporting a bug add logs from /tmp as separarate Text/plain attachments
Traceback (most recent call last):
  File "/sbin/anaconda", line 582, in <module>
    networkInitialize(ksdata)
  File "/usr/lib64/python3.6/site-packages/pyanaconda/network.py", line 1353, in networkInitialize
    logIfcfgFiles(msg)
  File "/usr/lib64/python3.6/site-packages/pyanaconda/network.py", line 239, in logIfcfgFiles
    ifcfglog.debug("all settings: %s", nm.nm_get_all_settings())
  File "/usr/lib64/python3.6/site-packages/pyanaconda/nm.py", line 760, in nm_get_all_settings
    settings = proxy.GetSettings()
  File "/usr/lib64/python3.6/site-packages/gi/overrides/Gio.py", line 172, in __call__
    None)
Glib.Error: g-dbus-error-quark: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: No such interface 'org.freedesktop.NetworkManager.Settings.Connection' on object at path /org
/freedesktop/NetworkManager/Settings/2 (19)
===