A German court has ruled that T-Mobile can make customers who buy the iPhone take out a T-Mobile contract as well and may continue to offer the device with a locked SIM card. This ruling comes two weeks after rival Vodafone obtained a preliminary injunction against T-Mobile prohibiting the carrier from selling iPhones that are locked to its network, leading T-Mobile to offer unlocked iPhones for 999 euros. It is unknown whether T-Mobile will continue…