Client: Fix client starting game multiple times
Client: Fix client starting game multiple times

Added mutex() protection and simple if to startGame() to
ensure that it will be performed only once. This is necessary
because if there are multiple servers running, eahc of them
will call the clients startGame() method.

Tbh I haven't tested this because it's almost 2 AM and I'm
tired as fuck. I'll test it tomorrow, however I'm pretty
sure that it works.

BafDyce/alcatraz_ctf,BafDyce/alcatraz_ctf