Fix GObject warning in tests
Fix GObject warning in tests

The subclass test caused the following warning:

  (lua5.2:14980): GLib-GObject-CRITICAL **: 13:02:03.551: Object class
  LgiTestFakeMonitor1 doesn't implement property 'network-metered' from
  interface 'GNetworkMonitor'

This new property was added in Gio 2.46. The fix here is to implement
that property. That should not cause problems with older versions of
Gio, because there the extra property would just be ignored.

Signed-off-by: Uli Schlachter <346c0ad49ac8427b61b3b55abbe37dc0ebd524f2@znc.in>

pavouk/lgi