fix incorrect use of .join() with newlines

[mpeter]

Assuming a puppet file with the following from ::apache::mod::pagespeed

additional_configuration      => [
    "ModPagespeedEnableCachePurge $mod_pagespeed_enable_cache_purge",
    "ModPagespeedAnalyticsID $analytics_id",
    'ModPagespeedDisallow */APOS/*',
    'ModPagespeedDisallow */jasperserver-pro/*',
],  

this is evaluated:

<% if @additional_configuration.is_a? Array -%>
<%= @additional_configuration.join('\n') %>
<% else -%>

resulting in this...

ModPagespeedEnableCachePurge On\nModPagespeedAnalyticsID UA-xxxx-1\nModPagespeedDisallow */APOS/*\nModPagespeedDisallow */jasperserver-pro/*

Using double quotes for the .join("\n") makes it work correctly:

ModPagespeedEnableCachePurge On
ModPagespeedAnalyticsID UA-xxxx-1
ModPagespeedDisallow */APOS/*
ModPagespeedDisallow */jasperserver-pro/*

[tphoney]

Great catch !!!. Thanks for the PR @mpeter