coreutils: correct next version in patch description

The patch that commit a728e2fe (coreutils: fix build against uclibc
snapshot) adds mentions the wrong coreutils version in its description.

Also fix the sign-of tag while at it.

Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>