add missing backoff to next_nameserver() retry_with_tcp case

diff --git a/dns/resolver.py b/dns/resolver.py
index 88eab13f36fd560379ccdf16e1063f57376d6de1..fe409e0efbc9ca043a0359b804fd66aa147976a6 100644 (file)
--- a/dns/resolver.py
+++ b/dns/resolver.py
@@ -592,7 +592,7 @@ class _Resolution(object):
             assert self.nameserver is not None
             self.tcp_attempt = True
             self.retry_with_tcp = False
-            return (self.nameserver, self.port, True)
+            return (self.nameserver, self.port, True, 0)
 
         backoff = 0
         if not self.current_nameservers: