Fix documentation for loadUser

src/main/edu/wisc/doit/uwphps/UserDetailsProvider.php

@@ -35,7 +35,7 @@ abstract class UserDetailsProvider
     }
 
     /**
-     * Map Shibboleth header values to an associative array.
+     * Returns the logged-in user
      *
      * @return UserDetails  currently authenticated user, null if not logged in
      */