change base64 code
Change-Id: I79b87ea28dc4c1f4172e83fdd2a194c5bf978c89
Issue-ID: VFC-1429
Signed-off-by: maopengzhang <zhang.maopeng1@zte.com.cn>
         full_url = combine_url(base_url, resource)
         headers = {'content-type': 'application/json', 'accept': 'application/json'}
         if user:
-            headers['Authorization'] = 'Basic %s' % base64.b64encode(bytes('%s:%s' % (user, passwd), "utf-8"))
+            headers['Authorization'] = 'Basic %s' % base64.b64encode(bytes('%s:%s' % (user, passwd), "utf-8")).decode()
         ca_certs = None
         if additional_headers:
             headers.update(additional_headers)