No exception on no answer when using dnspython

dkim/dnsplug.py

@@ -27,7 +27,7 @@ __all__ = [
 
 def get_txt_dnspython(name):
     """Return a TXT record associated with a DNS name."""
-    a = dns.resolver.query(name, dns.rdatatype.TXT)
+    a = dns.resolver.query(name, dns.rdatatype.TXT,raise_on_no_answer=False)
     for r in a.response.answer:
         if r.rdtype == dns.rdatatype.TXT:
             return b"".join(r.items[0].strings)