gnucash maint: Fix signed int overflow warning.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/2c910ed1 (commit)
	from  https://github.com/Gnucash/gnucash/commit/8d723f1b (commit)



commit 2c910ed1bba7afcec307bacba61131f4e181e2ec
Author: John Ralls <jralls at ceridwen.us>
Date:   Mon Jun 9 08:34:20 2014 -0700

    Fix signed int overflow warning.



Summary of changes:
 src/libqof/qof/gnc-numeric.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)