self signed cert subjAltName should be used as fallback

[David Britton]

Since we are using subjAltName, we should put the CN in there as well as in CN proper. If it's an IP, it will not get correctly matched by some algorithms (like pycurl) if it's only in the CN:

2014-10-29 17:16:33,203 ERROR [PoolThread-twisted.internet.reactor-1] Error contacting the server at https://129.115.192.2:8443/message-system.
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/landscape/broker/transport.py", line 71, in exchange
    message_api)
  File "/usr/lib/python2.7/dist-packages/landscape/broker/transport.py", line 45, in _curl
    headers=headers, cainfo=self._pubkey, curl=curl))
  File "/usr/lib/python2.7/dist-packages/landscape/lib/fetch.py", line 101, in fetch
    raise PyCurlError(e.args[0], e.args[1])
PyCurlError: Error 51: SSL: certificate subject name (129.115.192.2) does not match target host name '129.115.192.2'