I want to have a real node, doing real things. Why do i need this testnet?
I dunno, bitcoin.conf is empty by default so you might have set it unintentionally.
Also, depending on your use-case, you might not be needing the other entries that you've added to the config file.
BTW, aside from deletion, commenting the line will disable it just like what you did in rpcuser and rpcpassword.