We have a specific issue that a user uploaded a file to a bucket
geo-fenced to EU and one of the pieces appeared to be on a node in the
US. The country code of this node is set to SE (Sweden) in the satellite
DB. It turns out that some time ago MaxMind changed the country code of
this node's IP from Sweden to US, but this change hasn't been reflected
in the satellite's database.
So far the satellite updates the country code of a node only if its IP
changes. It was assumed that if the IP does not change, its country code
shouldn't change too. This turned to be a wrong assumption.
With this change, the satellite will look up the MaxMindDB on every
check-in to see if the country code of the node's IP has changed.
Change-Id: Icdf659b09be9fc6ad14601902032b35ba5ea78c4
