Fix failing nickserver lookup for @leap.se keys

Hi,

I have a gpgkey for my @leap.se email addr published on an external keyserver. A keyserver search finds two keys for my email address:

gpg --search-keys MYUSERNAME@leap.se
gpg: data source: https://sks.spodhuis.org:443
...

But nickserver fails to lookup:

$ curl -k -i --silent --max-time 10 -X GET -d address=MYUSERNAME@leap.se https://unstable.bitmask.net:6425
HTTP/1.1 404 Not Found
Date: Tue, 06 Dec 2016 10:53:40 GMT
Server: Apache
Content-Length: 14
X-Frame-Options: DENY

404 Not Found

(from redmine: created on 2016-12-06, relates #8648 (closed))