recipe/certificate_authority: use UTF-8 for CA certificate

The CertificateAuthority tool in ERP5 uses UTF8 encoding for certificates,
but by default OpenSSL does not. This cause an error when using non-ascii
characters:

```
The localityName field is different between CA certificate and the request
```

To solve the problem, the Certificate Authority recipe should use the same
encoding as ERP5, which requires adding `-utf8` option when invoking
OpenSSL.

For instance, creating a certificate with `localityName` Москва
will give the following with the default OpenSSL encoding:
`\C3\90\C2\9C\C3\90\C2\BE\C3\91\C2\81\C3\90\C2\BA\C3\90\C2\B2\C3\90\C2\B0`.

UTF8-encoding this same string gives `\D0\9C\D0\BE\D1\81\D0\BA\D0\B2\D0\B0`,
which is what ERP5 expects.

slapos/recipe/certificate_authority/certificate_authority.py

@@ -45,10 +45,11 @@ class CertificateAuthority:
         os.unlink(f)
     try:
       # no CA, let us create new one
-      popenCommunicate([self.openssl_binary, 'req', '-nodes', '-config',
-          self.openssl_configuration, '-new', '-x509', '-extensions',
-          'v3_ca', '-keyout', self.key, '-out', self.certificate,
-          '-days', '10950'], 'Certificate Authority %s\n' % uuid.uuid1())
+      popenCommunicate([self.openssl_binary, 'req', '-utf8', '-nodes',
+          '-config', self.openssl_configuration, '-new', '-x509',
+          '-extensions', 'v3_ca', '-keyout', self.key, '-out',
+          self.certificate, '-days', '10950'],
+          'Certificate Authority %s\n' % uuid.uuid1())
     except:
       try:
         for f in file_list: