Fixes #25535 - changed the config_files definition

Before this patch, the entire /var/www/html/pub directory was
backed up. In some cases leading to a config_files.tar.gz of
10's og Gigs.
This change ensures that only files that begin with katello- are
added during this phase.

definitions/features/foreman_server.rb

@@ -28,7 +28,7 @@ def plugins
       def config_files
         [
           '/etc/httpd',
-          '/var/www/html/pub',
+          '/var/www/html/pub/katello-*',
           '/etc/squid',
           '/etc/foreman',
           '/etc/selinux/targeted/contexts/files/file_contexts.subs',