Binary listening socket is not shorten

[Totktonada]

Since #574 tt sets the TT_IPROTO_LISTEN_DEFAULT environment variable. If it is too long, tarantool can't start with a message like the following:

F> can't initialize storage: bind, called on fd 19, aka unix/:(socket): Address already in use

This logic is present for a console socket. I propose to add it for the iproto socket too.

tt/cli/running/cluster_instance.go

Lines 83 to 88 in 8421eff

	consoleSocket, err := shortenSocketPath(inst.consoleSocket, inst.appDir)
	if err != nil {
	return err
	}
	cmd.Env = append(cmd.Env, "TT_CONSOLE_SOCKET_DEFAULT="+consoleSocket)
	cmd.Env = append(cmd.Env, "TT_IPROTO_LISTEN_DEFAULT="+"[{\"uri\":\""+inst.binaryPort+"\"}]")

The problem is reported by @andreyaksenov.