gnucash: fixed autoconf error by running autoreconf in the preconf hook

Note:

This can be considered a quick and dirty workaround but until we have
found a kind of generic solution for solving that issue we might have
to live with that.

error: possibly undefined macro: AM_GCONF_SOURCE_2

office/gnucash/gnucash.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../gnucash/gnucash.conf
-# Copyright (C) 2008 The OpenSDE Project
+# Copyright (C) 2008 - 2011 The OpenSDE Project
 # Copyright (C) 2004 - 2006 The T2 SDE Project
 # Copyright (C) 1998 - 2003 Clifford Wolf
 #
@@ -14,6 +14,9 @@
 # GNU General Public License can be found in the file COPYING.
 # --- SDE-COPYRIGHT-NOTE-END ---
 
+# workaround autoconf error: possibly undefined macro: AM_GCONF_SOURCE_2
+hook_add preconf 3 "autoreconf -v -I $(pkgprefix -r datadir gconf)/aclocal"
+
 var_append confopt ' ' '--disable-prefer-db1'
 pkginstalled openhbci && var_append confopt ' ' '--enable-hbci'
 var_append GCC_WRAPPER_REMOVE " " "-Werror"