patch releases: fix off by one in 1.16 branch info
patch releases: fix off by one in 1.16 branch info

1.16.15 has not been released yet, but it will be the last release for
the branch.

Signed-off-by: Tim Pepper <4807564e5a18784afafcf20dbdb5591e844b9075@vmware.com>

kubernetes/sig-release