gnucash maint: Update US Income Tax information for 2019.

[J.Alex Aycinena]

Updated	 via  https://github.com/Gnucash/gnucash/commit/24b46b1c (commit)
	from  https://github.com/Gnucash/gnucash/commit/e51bc45e (commit)



commit 24b46b1c3601bfcfaafa5f3209889520a224ed8a
Author: gnucash-dev <gnucash-dev at LenovoFedora30VM.home>
Date:   Mon Jan 20 17:28:49 2020 -0800

    Update US Income Tax information for 2019.



Summary of changes:
 libgnucash/tax/us/txf.scm | 56 +++++++++++++++++++++++------------------------
 1 file changed, 28 insertions(+), 28 deletions(-)