[CentOS] [Infra] - Planned outage/migration : CentOS forums

Due to a hardware/DC relocate operation, we'll have to move the existing CentOS forums instance (hosted on https://www.centos.org/forums) to a new node.

Migration is scheduled for """"Monday December 16th, 8:00 am UTC time"""". You can convert to local time with $(date -d '2019-12-16 8:00 UTC')

The expected "downtime" is estimated to ~20 minutes , time needed to :

- freeze forums instance - backup instance data (DB + files) - import data to new host and validate - enable the httpd redirection to the new host

Worth knowing that during the migration process, the forums instance will not be available.

Thanks for your comprehending and patience.