Refresh generic wxListCtrl after removing a column from it.

Deleting a column still kept it on display, at least until the next refresh,
e.g. resizing the window was enough to make it disappear.

Simply add a call to Refresh() to ensure that the column does disappear when
deleted.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69955 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/listctrl.cpp

@@ -4820,6 +4820,10 @@ bool wxGenericListCtrl::DeleteColumn( int col )
     // if we don't have the header any longer, we need to relayout the window
     // if ( !GetColumnCount() )
 
+
+    // Ensure that the non-existent columns are really removed from display.
+    Refresh();
+
     return true;
 }