fix extended controls: xchangeproperty unexpected keyord arg

Traceback (most recent call last):
  File "/[...]/python3.5/site-packages/tooncher/__init__.py", line 162, in launch
    toggle_keysym_name=extended_keyboard_control_toggle_keysym_name,
  File "/[...]/python3.5/site-packages/tooncher/controls.py", line 151, in run
    mode=X.PropModeReplace,
TypeError: change_property() got an unexpected keyword argument 'property_type'

tooncher/controls.py

@@ -145,7 +145,7 @@ class ExtendedControls:
         )
         self._primary_engine_window.change_property(
             self.xdisplay.intern_atom(EXTENDED_CONTROLS_PID_XPROPERTY_NAME),
-            property_type=Xatom.CARDINAL,
+            Xatom.CARDINAL,
             format=32,
             data=[os.getpid()],
             mode=X.PropModeReplace,