py3: fix CSR encoding inside framework

csr must be in string because framework excpects only strings, so we
have to decode it back

https://fedorahosted.org/freeipa/ticket/4985

Reviewed-By: Christian Heimes <cheimes@redhat.com>

ipaserver/plugins/cert.py

@@ -804,7 +804,9 @@ class cert_request(Create, BaseCertMethod, VirtualCommand):
         try:
             # re-serialise to PEM, in case the user-supplied data has
             # extraneous material that will cause Dogtag to freak out
-            csr_pem = csr_obj.public_bytes(serialization.Encoding.PEM)
+            # keep it as string not bytes, it is required later
+            csr_pem = csr_obj.public_bytes(
+                serialization.Encoding.PEM).decode('utf-8')
             result = self.Backend.ra.request_certificate(
                 csr_pem, profile_id, ca_id, request_type=request_type)
         except errors.HTTPRequestError as e:

ipaserver/plugins/dogtag.py

@@ -1634,7 +1634,7 @@ class ra(rabase.rabase, RestClient):
         self.debug('%s.request_certificate()', type(self).__name__)
 
         # Call CMS
-        template = '''<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+        template = u'''<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
             <CertEnrollmentRequest>
                 <ProfileID>{profile}</ProfileID>
                 <Input id="i1">