gnucash maint: Fix test-gnc-datetime failure on Ubunutu.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/b4058924 (commit)
	from  https://github.com/Gnucash/gnucash/commit/c49b45d8 (commit)



commit b40589244c70dcf88c868da5c5f32b7ac1d123c9
Author: John Ralls <jralls at ceridwen.us>
Date:   Mon Mar 22 14:18:24 2021 -0700

    Fix test-gnc-datetime failure on Ubunutu.



Summary of changes:
 libgnucash/engine/test/gtest-gnc-datetime.cpp | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)