x509: CRL: add tests for non-critical extension

The 'critical' boolean can be set to false in two ways:
- by leaving it implicit (test data generated by openssl)
- by explicitly setting it to false (generated by hand)
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 5740b11..df4834d 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -48,6 +48,10 @@
 
 crl-idp.pem: $(test_ca_crt) $(test_ca_key_file_rsa) $(test_ca_config_file)
 	$(OPENSSL) ca -gencrl -batch -cert $(test_ca_crt) -keyfile $(test_ca_key_file_rsa) -key $(test_ca_pwd_rsa) -config $(test_ca_config_file) -name test_ca -md sha256 -crldays 3653 -crlexts crl_ext_idp -out $@
+all_final += crl-idp.pem
+crl-idpnc.pem: $(test_ca_crt) $(test_ca_key_file_rsa) $(test_ca_config_file)
+	$(OPENSSL) ca -gencrl -batch -cert $(test_ca_crt) -keyfile $(test_ca_key_file_rsa) -key $(test_ca_pwd_rsa) -config $(test_ca_config_file) -name test_ca -md sha256 -crldays 3653 -crlexts crl_ext_idp_nc -out $@
+all_final += crl-idpnc.pem
 
 cli_crt_key_file_rsa = cli-rsa.key
 cli_crt_extensions_file = cli.opensslconf