wxGUI: fix d.vect dialog when loading layer without db connection, caused by https://trac.osgeo.org/grass/changeset/72547

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@72628 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_core/gselect.py

@@ -1139,7 +1139,7 @@ class ColumnSelect(ComboCtrl):
                             self.columns.remove(key)
                         except ValueError:
                             pass
-        except (KeyError, ValueError):
+        except (KeyError, ValueError, GException):
             self.columns[:] = []
 
         # update list