Fix test wrt. OPENSSL_CONF

This test is supposed to verify the path of the default OpenSSL config
file; it will fail, though, if OPENSSL_CONF is explicitly set, so we
explicitly unset this environment variable for this test.

Author: cmb69

ext/openssl/tests/check_default_conf_path.phpt

@@ -6,6 +6,8 @@ if (substr(PHP_OS, 0, 3) != 'WIN') {
     die('skip windows only test');
 }
 ?>
+--ENV--
+OPENSSL_CONF=
 --FILE--
 <?php