Fix casing for external site app

external/appinfo/info.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <info>
 	<id>external</id>
-	<name>External Sites</name>
+	<name>External sites</name>
 	<description>
 		This application allows an admin to add a link in the ownCloud web interface
 		Apps menu that points to an external website. By simply entering the URL and
@@ -10,10 +10,10 @@
 		external site appears as if it is part of ownCloud but, in fact, this can be
 		any external URL.
 
-		Note that the External Site link must use the same type of encryption as
+		Note that the external site link must use the same type of encryption as
 		provided by ownCloud. In other words, if ownCloud is hosted on HTTPS, the
 		link in the external site must also be HTTPS. The same is also true for HTTP.
-		More information is available in the External Sites documentation.
+		More information is available in the External sites documentation.
 	</description>
 	<licence>AGPL</licence>
 	<author>Frank Karlitschek</author>

external/templates/settings.php

@@ -1,6 +1,6 @@
 <form id="external">
 	<div class="section">
-		<h2><?php p($l->t('External Sites'));?></h2>
+		<h2><?php p($l->t('External sites'));?></h2>
 		<p>
 			<em><?php p($l->t('Please note that some browsers will block displaying of sites via http if you are running https.')); ?></em>
 			<br>