wxGUI/vdigit: fix 'Copy categories/features' editing tool if you sele…

…ct only one feature (#1816)

gui/wxpython/vdigit/mapwindow.py

@@ -1092,7 +1092,7 @@ def _onRightUp(self, event):
                     fid,
                 ]
             )
-        elif action in ("copyCats", "copyAttrs"):
+        elif action in ("copyCats", "copyAttrs") and hasattr(self, "copyCatsIds"):
             if action == "copyCats":
                 if (
                     self.digit.CopyCats(