This was originally a reply to Falterfire, but I royally screwed up the quoting and couldn't fix it, so pretend I'm quoting him here.
If a contract is contradicted by law, the terms of that contract may not be enforceable, regardless of whether or not you agreed to them. In this case, Germany has already said that digital licenses are sold and are the same as any other product. If the contract or TOS says otherwise, the TOS will likely be wrong. Not the law.
I can sign a contract saying I agree to let you jack me in the face, but since assault is illegal, you would still likely go to jail. The law trumps the contract. This is really no different.