Add reaping_frequency for MySQL production DB

This helped avoid ActiveRecord::ConnectionTimeoutError errors for
Sidekiq on GitLab Cloud.
Support symlinked public/uploads for backp restore

The backup restore code moves any existing uploads directory out of the
way before restoring the copy from the backup. If public/uploads was a
symlink, this move would replace the symlink. This commit avoids this
issue by first resolving any symlinks in the uploads path.
 Merge branch 'db_reaping_frequency' into 'master'

DB Reaping Frequency
 Merge branch 'backup_uploads_symlink' into 'master'

Backup Uploads Symlink