Remove trailing whitespace.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>

library/HTMLPurifier/AttrDef/HTML/FrameTarget.php

@@ -5,16 +5,16 @@
  */
 class HTMLPurifier_AttrDef_HTML_FrameTarget extends HTMLPurifier_AttrDef_Enum
 {
-    
+
     public $valid_values = false; // uninitialized value
     protected $case_sensitive = false;
-    
+
     public function __construct() {}
-    
+
     public function validate($string, $config, $context) {
         if ($this->valid_values === false) $this->valid_values = $config->get('Attr', 'AllowedFrameTargets');
         return parent::validate($string, $config, $context);
     }
-    
+
 }