Fix group on FreeBSD

  The server::backup class don't use the correct information from
  mysql::params about backupdirgroup. Because on FreeBSD the group root
  doesn't exist it should use wheel instead. This difference are
  correctly configure inside mysql::params but not inside server::backup

Author: jas01

Diff for: manifests/server/backup.pp

@@ -31,7 +31,7 @@
 # @param backupcompress
 #   Whether or not to compress the backup (when using the mysqldump provider)
 # @param backupmethod
-#   The execution binary for backing up. ex. mysqldump, xtrabackup, mariabackup 
+#   The execution binary for backing up. ex. mysqldump, xtrabackup, mariabackup
 # @param backuprotate
 #   Backup rotation interval in 24 hour periods.
 # @param ignore_events
@@ -56,7 +56,7 @@
 # @param execpath
 #   Allows you to set a custom PATH should your MySQL installation be non-standard places. Defaults to `/usr/bin:/usr/sbin:/bin:/sbin`.
 # @param provider
-#   Sets the server backup implementation. Valid values are: 
+#   Sets the server backup implementation. Valid values are:
 # @param maxallowedpacket
 #   Defines the maximum SQL statement size for the backup dump script. The default value is 1MB, as this is the default MySQL Server value.
 # @param optional_args
@@ -68,7 +68,7 @@
   $backupdir          = undef,
   $backupdirmode      = '0700',
   $backupdirowner     = 'root',
-  $backupdirgroup     = 'root',
+  $backupdirgroup     = $mysql::params::root_group,
   $backupcompress     = true,
   $backuprotate       = 30,
   $backupmethod       = undef,
@@ -86,7 +86,7 @@
   $provider           = 'mysqldump',
   $maxallowedpacket   = '1M',
   $optional_args      = [],
-) {
+) inherits mysql::params {
 
   if $prescript and $provider =~ /(mysqldump|mysqlbackup)/ {
     warning(translate("The 'prescript' option is not currently implemented for the %{provider} backup provider.",