package/libnss: security bump to version 3.42.1

Fixes the following security issues:

(3.41) CVE-2018-12404: Cache side-channel variant of the Bleichenbacher
attack

(3.42.1) CVE-2018-18508: Add additional null checks to several CMS functions
to fix a rare CMS crash.  Thanks to Hanno Böck and Damian Poddebniak for the
discovery and fixes

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>