r23621 - gnucash/trunk/src/gnome - Fix compile warning introduced in r23602

[Geert Janssens]

Author: gjanssens
Date: 2013-12-26 08:47:49 -0500 (Thu, 26 Dec 2013)
New Revision: 23621
Trac: http://svn.gnucash.org/trac/changeset/23621

Modified:
   gnucash/trunk/src/gnome/top-level.c
Log:
Fix compile warning introduced in r23602

Quote from gnucash-devel:
"I think this introduced a "might be used uninitialized" warning in
src/gnome/top-level.c with my particular version of gcc.

Initializing *file_guid with NULL in gnc_restore_all_state() fixes
the warning, see below."

Author:    Herbert Thoma <herbert.thoma at iis.fraunhofer.de>