wxIClass: fix deleting areas

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@49816 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/iclass/digit.py

@@ -60,6 +60,9 @@ class IClassVDigitWindow(VDigitWindow):
     def _addRecord(self):
         return False
         
+    def _updateATM(self):
+        pass
+        
     def GetCurrentCategory(self):
         """!Returns current category (class).