entry: Set use-underline in popover GtkToolButtons

gtk/gtkentry.c

@@ -9372,6 +9372,7 @@ append_bubble_action (GtkEntry     *entry,
                       gboolean      sensitive)
 {
   GtkToolItem *item = gtk_tool_button_new (NULL, label);
+  gtk_tool_button_set_use_underline (GTK_TOOL_BUTTON (item), TRUE);
   g_object_set_data (G_OBJECT (item), I_("gtk-signal"), (char *)signal);
   g_signal_connect (item, "clicked", G_CALLBACK (activate_bubble_cb), entry);
   gtk_widget_set_sensitive (GTK_WIDGET (item), sensitive);