Remove unused exceptions.

lib/SimpleSAML/Error/NoAvailableIDP.php

-<?php
-/**
- * Simple exception to model the NoAvailableIDP SAML error.
- *
- * @author Jaime Pérez Crespo, UNINETT AS <jaime.perez@uninett.no>
- * @package SimpleSAMLphp
- */
-
-namespace SimpleSAML\Error;
-
-
-class NoAvailableIDP extends \SimpleSAML_Error_Exception
-{
-
-}
\ No newline at end of file

lib/SimpleSAML/Error/NoSupportedIDP.php

-<?php
-/**
- * Simple exception to model the NoSupportedIDP SAML error.
- *
- * @author Jaime Pérez Crespo, UNINETT AS <jaime.perez@uninett.no>
- * @package SimpleSAMLphp
- */
-
-namespace SimpleSAML\Error;
-
-
-class NoSupportedIDP extends \SimpleSAML_Error_Exception
-{
-
-}
\ No newline at end of file