Add PHP5-style constructor

functions/addressbook.php

@@ -425,12 +425,19 @@ class AddressBook {
     var $add_extra_field = false;
 
     /**
-     * Constructor function.
+     * Constructor (PHP5 style, required in some future version of PHP)
      */
-    function AddressBook() {
+    function __construct() {
         $this->localbackendname = _("Personal Address Book");
     }
 
+    /**
+     * Constructor (PHP4 style, kept for compatibility reasons)
+     */
+    function AddressBook() {
+        self::__construct();
+    }
+
     /**
      * Return an array of backends of a given type,
      * or all backends if no type is specified.