Revert "Use concat_output for file content source, so we get the old file Filebucketed on change"

This reverts commit 3a4a13cc544fc8dbe81a93da5c32ef570c361285.

This change uses different module for concating. Reverting till the new module
is packaged.
Automatic commit of package [foreman-installer-puppet-dhcp] minor release [0-5.3a4a13c].