Simplify detection of %s in custom_command

This uses the cheaper include? to determine if %s is in custom_command.
It also simplifies the expression with a safe operator.

lib/puppet_x/bodeco/archive.rb

@@ -44,7 +44,7 @@ def extract(path = root_dir, opts = {})
         custom_command = opts.fetch(:custom_command, nil)
         options = opts.fetch(:options)
         Dir.chdir(path) do
-          cmd = if custom_command && custom_command =~ %r{%s}
+          cmd = if custom_command&.include?('%s')
                   custom_command % @file_path
                 elsif custom_command
                   "#{custom_command} #{options} #{@file_path}"