Use UTC instead of unavailable timezone in test

Author: duncan3dc

ext/date/tests/timestamp-in-dst.phpt

@@ -1,10 +1,9 @@
 --TEST--
 Format timestamp in DST test
 --INI--
-date.timezone=CEST
+date.timezone=UTC
 --FILE--
 <?php
-error_reporting(E_ALL & ~E_WARNING); // hide e_warning warning about timezones
 var_dump( date_create( '@1202996091' )->format( 'c' ) );
 ?>
 --EXPECT--