use updated "Strip http://php.net" method for more news links

Following on from a similar change in 47f8ecc688, update more places
where we manipulate the URL.

conferences/index.php

@@ -29,7 +29,7 @@ $panels = '<p class="prepend"><a href="https://wiki.php.net/conferences">Want to
 
 
 foreach($frontpage as $entry) {
-    $link = substr($entry["id"], 15); // Strip http://php.net/
+    $link = preg_replace('~^(http://php.net/|https://www.php.net/)~', '', $entry["id"]);
     $id   = parse_url($entry["id"], PHP_URL_FRAGMENT);
     $date = date_format(date_create($entry["updated"]), 'Y-m-d');
     $content .= '<div class="newsentry">';