tests: fix a spurious failure due to truncated timestamps Fixes automake bug#11346. * t/self-check-is_newest.tap: Apparently, on some systems (or file systems), "touch -r" can truncate timestamps :-( Work around that. Co-authored-by: Peter Breitenlohner <peb@mppmu.mpg.de> Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>