I am applying to another LL.M. due to the fact that it is hard to find a job at a law firm at the moment. Is it a waste of time?

I wouldn't say it's a waste of time because the whole experience must be very exciting and if I were you I'd choose a totally different country for the second LLM. But it surely will be a waste of money... even if you're planning on moving to a academic career I wouldn't advise you to take up another LLM. Why don't you try another degree? Maybe an MLitt?