wxGUI: fixing trac https://trac.osgeo.org/grass/ticket/191 (merge devbr6, https://trac.osgeo.org/grass/changeset/31760)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@31761 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_modules/location_wizard.py

@@ -2042,7 +2042,7 @@ class LocationWizard(wx.Object):
         except:
             pass
 
-        if dtoptions != None:
+        if dtoptions != {}:
             dtrans = ''
             # open a dialog to select datum transform number
             dlg = SelectDatumDialog(self.parent, datums=dtoptions)