- Don't create link to not existing css file for dummy task

- rename addresses.css to addressbook.css (now matches with task name)

skins/default/includes/links.html

@@ -1,7 +1,9 @@
 <link rel="index" href="$__comm_path" />
 <link rel="shortcut icon" href="/images/favicon.ico"/>
 <link rel="stylesheet" type="text/css" href="/common.css" />
-<roundcube:if condition="env:task != 'login'" /><link rel="stylesheet" type="text/css" href="/<roundcube:exp expression="env:task=='addressbook'?'addresses':env:task" />.css" /><roundcube:endif />
+<roundcube:if condition="env:task != 'login' && env:task != 'dummy'" />
+<link rel="stylesheet" type="text/css" href="/<roundcube:var name="env:task" />.css" />
+<roundcube:endif />
 <roundcube:if condition="browser:ie" />
 <!--[if lte IE 8]><link rel="stylesheet" type="text/css" href="/iehacks.css" /><![endif]-->
 <!--[if lte IE 6]><link rel="stylesheet" type="text/css" href="/ie6hacks.css" /><![endif]-->