Related: tdf#127782 call signal_expanded after expansion in gtk case

which is the same as the gen one

Change-Id: Ia93598bb88d5a3f93c62e7096f8bc4ca69698a19
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/86563
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/vcl/unx/gtk3/gtk3gtkinst.cxx b/vcl/unx/gtk3/gtk3gtkinst.cxx
index d52fb78..c6dee46 100644
--- a/vcl/unx/gtk3/gtk3gtkinst.cxx
+++ b/vcl/unx/gtk3/gtk3gtkinst.cxx
@@ -12602,7 +12602,6 @@
    {
        GtkInstanceExpander* pThis = static_cast<GtkInstanceExpander*>(widget);
        SolarMutexGuard aGuard;
        pThis->signal_expanded();

        GtkWidget *pToplevel = gtk_widget_get_toplevel(GTK_WIDGET(pExpander));

@@ -12625,6 +12624,8 @@

            gtk_window_resize(GTK_WINDOW(pToplevel), nToplevelWidth, nToplevelHeight);
        }

        pThis->signal_expanded();
    }

public: