gnucash maint: Use proper GtkAction function instead of generic g_object call

[Geert Janssens]

Updated	 via  https://github.com/Gnucash/gnucash/commit/9c9068cf (commit)
	from  https://github.com/Gnucash/gnucash/commit/f89a40e3 (commit)



commit 9c9068cf5a7bbfd86eacfd62fdfa515b533ae651
Author: Geert Janssens <geert at kobaltwit.be>
Date:   Mon Sep 24 18:24:40 2018 +0200

    Use proper GtkAction function instead of generic g_object call



Summary of changes:
 gnucash/gnome-utils/gnc-plugin.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)