Clean up: remove redundant '\n' in Create

Signed-off-by: Lei Jitang <leijitang@huawei.com>

daemon/create.go

@@ -70,7 +70,7 @@ func (daemon *Daemon) Create(config *runconfig.Config, hostConfig *runconfig.Hos
 		return nil, nil, err
 	}
 	if !config.NetworkDisabled && daemon.SystemConfig().IPv4ForwardingDisabled {
-		warnings = append(warnings, "IPv4 forwarding is disabled.\n")
+		warnings = append(warnings, "IPv4 forwarding is disabled.")
 	}
 	if hostConfig == nil {
 		hostConfig = &runconfig.HostConfig{}