qtdragon -add a default 'factor' to avoid error message

An error message is displayed (that is really not the problem)
 if linuxcnc doesn't quite load in the right sequence.
 If the 'metric changed' message was not called on startup -
 factor was never set

Author: c-morley

share/qtvcp/screens/qtdragon/qtdragon_handler.py

@@ -75,6 +75,7 @@ def __init__(self, halcomp, widgets, paths):
         KEYBIND.add_call('Key_Less','on_keycall_angular_jograte',0)
 
         # some global variables
+        self.factor = 1.0
         self._spindle_wait = False
         self.probe = None
         self.default_setup = os.path.join(PATH.CONFIGPATH, "default_setup.html")