Fix bug Multiple Servers with Tmux

Hi
I would like to use your script to run multiple servers.
I made an installation per server.
I change the default ports and "servicename" for change tmux name session.
But the script only check the existence of a tmux session.
And the script returns, the service is already running.
So I added the "$servicename" to check.

I suppose this bug impacts all scripts using Tmux.