NewServer() arg "backing" named "socket" in NewReplicaServer

[mixmasala]

Small issue: the argument naming confused me for a moment.

diff --git a/server/replica.go b/server/replica.go
index e957654..4e3d253 100644
--- a/server/replica.go
+++ b/server/replica.go
@@ -33,7 +33,7 @@ type Replica struct {
 }

 // NewReplica creates a new Replica server.
-func NewReplica(name string, socket string, config Config) *Replica {
+func NewReplica(name string, backing string, config Config) *Replica {
    r := &Replica{}
    r.log = common.NewLogger(name)
    r.name = name
@@ -49,7 +49,7 @@ func NewReplica(name string, socket string, config Config) *Replica {

    r.config.Store(config)

-   r.shard = NewShard(name, socket, config)
+   r.shard = NewShard(name, backing, config)

    return r
 }