It's a vacuum. Which means that there aren't atoms to get hot or cold. Which means there is no medium with which to exchange heat to cool something down, unless you are willing to bring a bunch of your own air to blow over the servers and then vent into space. Which means bringing an awful lot of air with you.
A server sitting in the vacuum of space would quickly over heat for lack of ventilation (if it didn't get destroyed because it wasn't structurally engineered to run in a vacuum).