Optimize DnsRecord.get_unique()
Optimize DnsRecord.get_unique()

Don't load the FQDN twice.

Change-Id: I96809b5b034ff3b77e377bc0b706bdfff4603ddf
Reviewed-by: Zoltan Sebestyen <be2314d0afde2d2352aeb623a228e572c9b6cb8b@morganstanley.com>

stdweird/aquilon,guillaume-philippon/aquilon,quattor/aquilon,quattor/aquilon,quattor/aquilon,guillaume-philippon/aquilon,stdweird/aquilon,stdweird/aquilon,guillaume-philippon/aquilon