Resolves: tdf#126304 resizing the extension manager breaks redraw

Change-Id: I1211c90a72048f868ec7ba7a7b6bed452ae8ac4b
Reviewed-on: https://gerrit.libreoffice.org/75791
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/desktop/source/deployment/gui/dp_gui_extlistbox.cxx b/desktop/source/deployment/gui/dp_gui_extlistbox.cxx
index fc8a480..6a7c87a 100644
--- a/desktop/source/deployment/gui/dp_gui_extlistbox.cxx
+++ b/desktop/source/deployment/gui/dp_gui_extlistbox.cxx
@@ -702,6 +702,7 @@ void ExtensionBox_Impl::SetupScrollBar()
void ExtensionBox_Impl::Resize()
{
    RecalcAll();
    Invalidate();
}

void ExtensionBox_Impl::SetDrawingArea(weld::DrawingArea* pDrawingArea)