Upgrade to 9.4.2

We skipped 9.4.1 & 9.4.0: there were buils issues on FreeBSD

9.4.2: https://sourceforge.net/p/bacula/mailman/message/36580007/
9.4.1: https://www.bacula.org/bacula-release-9-4-1/
9.4.0: https://sourceforge.net/p/bacula/mailman/message/36495161/

https://www.bacula.org/bacula-release-9-4-0/