Use standard way for linking documentation.

libraries/common.lib.php

@@ -1936,8 +1936,8 @@ function PMA_checkParameters($params, $die = true, $request = true)
         if (!isset($GLOBALS[$param])) {
             $error_message .= $reported_script_name
                 . ': Missing parameter: ' . $param
-                . ' <a href="./Documentation.html#faqmissingparameters"'
-                . ' target="documentation"> (FAQ 2.8)</a><br />';
+                . PMA_showDocu('faqmissingparameters')
+                . '<br />';
             $found_error = true;
         }
     }