gnucash maint: Fix another typo in README

[Frank H.Ellenberger]

Updated	 via  https://github.com/Gnucash/gnucash/commit/51d1bc77 (commit)
	from  https://github.com/Gnucash/gnucash/commit/63fc399c (commit)



commit 51d1bc775d2881d8678412a2bc3cccac7b2c9e0e
Author: fell <frank.h.ellenberger at gmail.com>
Date:   Tue Apr 17 22:50:17 2018 +0200

    Fix another typo in README



Summary of changes:
 README | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)