"publish was broken by timeout" when WriteTimeout=0

[MattBrittan]

I am getting "publish was broken by timeout" on approximately 10% of publish calls with the latest master.

It appears that this is due to PR #326 which calls time.After(c.options.WriteTimeout) (client.go:604). If WriteTimeout is 0 (the default) then its possible that both options in the select statement will be ready so one will be chosen at random. Unfortunately when this happens the publish message is lost (I do not have code to deal with that because it should not be necessary with the filestore enabled).