Domain lookups fail for domains hosted by wordpress.com

[François Marier]

Instead of returning NXDOMAIN, the wordpress.com DNS server returns a status of NOERROR and bogus CNAME record instead of an SRV record:

$ dig SRV _avatars._tcp.retakethe.net

; <<>> DiG 9.7.0-P1 <<>> SRV _avatars._tcp.retakethe.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18247
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;_avatars._tcp.retakethe.net. IN SRV

;; ANSWER SECTION:
_avatars._tcp.retakethe.net. 13424 IN CNAME retakethe.net.

We therefore need to check that "(answer['data'] == 'SRV')" in public/views.py:lookup_avatar_server().