cert-request: raise error when request fails

Fix a regression in recent change to request cert via Dogtag REST
API.  'ra.request_certificate' was no longer raising
CertificateOperationError when the cert request failed.  Inspect the
request result to determine if the request completed, and raise if
it did not.

Fixes: https://fedorahosted.org/freeipa/ticket/6309
Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>

ipaserver/plugins/dogtag.py

@@ -1678,6 +1678,10 @@ class ra(rabase.rabase, RestClient):
             return cmd_result
         certinfo = entries[0]
 
+        if certinfo['requestStatus'] != 'complete':
+            raise errors.CertificateOperationError(
+                    error=certinfo.get('errorMessage'))
+
         if 'certId' in certinfo:
             cmd_result = self.get_certificate(certinfo['certId'])
             cert = ''.join(cmd_result['certificate'].splitlines())