Properly checking response code from update

src/daneupdate/utils/tlsa/liveupdate_config.py

@@ -14,6 +14,7 @@ from dns.name import Name
 from dns.name import from_text as name_from_text
 from dns.nameserver import Do53Nameserver
 from dns.query import tcp
+from dns.rcode import Rcode
 from dns.rdataclass import RdataClass
 from dns.rdataset import Rdataset
 from dns.rdatatype import TLSA, RdataType
@@ -200,9 +201,10 @@ class _DnsServerInfo(object):
             if dry_run:
                 continue
             response = tcp(q=update, where=self.str_ip)
-            if not response.errors:
+            resp_rcode = response.rcode()
+            if resp_rcode != Rcode.NOERROR:
                 raise RuntimeError(
-                    f'Update response container errors: {response.errors}')
+                    f'Update failed, return code {resp_rcode!r}')
 
 
 _serverinfo_cache = dict[Configuration, list[_DnsServerInfo]]()