use configurable password field instead of the hardcoded one

git-svn-id: https://semanticscuttle.svn.sourceforge.net/svnroot/semanticscuttle/trunk@630 b3834d28-1941-0410-a4f8-b48e95affb8f

src/SemanticScuttle/Service/AuthUser.php

@@ -169,7 +169,7 @@ class SemanticScuttle_Service_AuthUser extends SemanticScuttle_Service_User
         //we need to update the local database.
         $user = $this->getUserByUsername($username);
         $this->_updateuser(
-            $user['uId'], 'password',
+            $user['uId'], $this->getFieldName('password'),
             $this->sanitisePassword($password)
         );