docs: fix bug 7628699

Change-Id: I7e8ca29910345559993cf415c2a89a21f50e4e17

Author: Robert Ly

docs/html/develop/index.jd

@@ -52,7 +52,7 @@ src="http://1.bp.blogspot.com/-6K1kfNOdek8/T72bXvtTSQI/AAAAAAAABmw/kYzmJt0_328/s
                    <h2>In-app Subscriptions with Trials</h2>
                    <p>You can now set up a <strong>free trial period</strong> for any Google Play in-app subscription, making it easy for users try your subscriber content before automatically converting to a full subscription. Free trials give you a new way to bring users into your products and engage them effectively. </p>
                    <p><a class="button"
-href="http://dirkbd.mtv:8809/guide/google/play/billing/billing_subscriptions.html#trials">Read
+href="{@docRoot}guide/google/play/billing/billing_subscriptions.html#trials">Read
 more</a></p>
                    </div>                
                 </li>