NCBC-375: preferring ipv4-address

If you configure a couchbase-server with hostname instead of ip (ipv4, you
can't enter an ipv6 address via web interface), the .net client library
refuses the connection. This fix ensures that the ipv4-address is chosen
over the ipv6-address when a connection is made.

Additional info: MB-6378

Change-Id: I0278d332ce16ac42158420fb147b4a00fae2e2dd
Reviewed-on: http://review.couchbase.org/33084
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Reviewed-by: Stefan Dirks <sdirks456@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>