Remove unused use-statements

Author: tvdijen

tests/XML/ds/X509CertificateTest.php

@@ -6,12 +6,9 @@
 
 use DOMDocument;
 use PHPUnit\Framework\TestCase;
-use SimpleSAML\Assert\AssertionFailedException;
 use SimpleSAML\XML\DOMDocumentFactory;
 use SimpleSAML\XMLSecurity\TestUtils\PEMCertificatesMock;
 use SimpleSAML\XMLSecurity\XML\ds\X509Certificate;
-use SimpleSAML\XMLSecurity\XMLSecurityDSig;
-use SimpleSAML\XMLSecurity\XMLSecurityKey;
 
 /**
  * Class \SimpleSAML\XMLSecurity\XML\ds\X509CertificateTest