fix get cdrstats from redis and a small rpc problem

cmd/cgr-engine/cgr-engine.go

@@ -469,7 +469,7 @@ func main() {
 			cdrStats.AddQueue(engine.NewCdrStatsFromCdrStatsCfg(cfg.CDRStatConfig), &out)
 		}
 		server.RpcRegister(cdrStats)
-		server.RpcRegister(apier.CDRStatsV1{cdrStats}) // Public APIs
+		server.RpcRegister(&apier.CDRStatsV1{cdrStats}) // Public APIs
 	}
 
 	var cdrsChan chan struct{}

engine/storage_redis.go

@@ -688,7 +688,7 @@ func (rs *RedisStorage) GetAllCdrStats() (css []*CdrStats, err error) {
 		if err != nil {
 			continue
 		}
-		var cs *CdrStats
+		cs := &CdrStats{}
 		err = rs.ms.Unmarshal(value, cs)
 		css = append(css, cs)
 	}