Fix connection issue in Amazon Keyspaces

In Amazon Keyspaces, system.local returns the localhost address and
system.peers returns a host that contains the same hostID as localhost.
This causes the connection issue in refreshRing(), where host address is
overwritten with the localhost address and a host with the same hostID
results in the "cannot find host" error.

This commit fixes GetHosts() so that it ignores localhost if the same
hsotID is included in peerHosts.

Author: yomipq

host_source.go

@@ -722,7 +722,20 @@ func (r *ringDescriber) GetHosts() ([]*HostInfo, string, error) {
 		return r.prevHosts, r.prevPartitioner, err
 	}
 
-	hosts := append([]*HostInfo{localHost}, peerHosts...)
+	var hasSameHostID bool
+	for _, h := range peerHosts {
+		if h.HostID() == localHost.HostID() {
+			hasSameHostID = true
+		}
+	}
+
+	var hosts []*HostInfo
+	if hasSameHostID {
+		hosts = peerHosts
+	} else {
+		hosts = append([]*HostInfo{localHost}, peerHosts...)
+	}
+
 	var partitioner string
 	if len(hosts) > 0 {
 		partitioner = hosts[0].Partitioner()