Minimal fix for dnspython 2.0.0 compatibility (still works with 1.16.0)

CHANGES

@@ -1,7 +1,8 @@
-1.2.2
+1.2.2 2020-08-09
  - Improve README.md formating for markdown display on pypi
  - Improve documentation in dkimpy-milter.conf (5) and README.md for signing
    for multiple domains (Thanks to Stefano Rivera)
+ - Minimal fix for dnspython 2.0.0 compatibility (still works with 1.16.0)
 
 1.2.1 2020-01-04
  - Fix expand option not to fail if files are missing since socket activation

dkimpy_milter/dnsplug.py

@@ -127,7 +127,7 @@ def DNSLookup_dnspython(name,qtype,tcpfallback=True,timeout=5):
       elif qtype == 'PTR':
         retVal.append(((name, qtype), rdata.target.to_text(True)))
       elif qtype == 'TXT' or qtype == 'SPF':
-        retVal.append(((name, qtype), rdata.strings))
+        retVal.append(((name, qtype), list(rdata.strings)))
   except dns.resolver.NoAnswer:
     pass
   except dns.resolver.NXDOMAIN: