examples: remove sony.com from 10-at-a-time

Prior to this change the 10-at-a-time example showed CURLE_RECV_ERROR
for the sony website because it ends the connection when the request is
missing a user agent.

docs/examples/10-at-a-time.c

@@ -62,7 +62,6 @@ static const char *urls[] = {
   "http://www.uefa.com",
   "http://www.ieee.org",
   "http://www.apple.com",
-  "http://www.sony.com",
   "http://www.symantec.com",
   "http://www.zdnet.com",
   "http://www.fujitsu.com",