My first response is do the degree that interests you the most. If you're interest wains it gets tough to get through.
As has been said it makes no difference whether you have a Physics degree or Aero degree on being a pilot. But with regards to work afterwards if the pilot thing doesn't work out, Engineering will give you a lot of opportunities. From my graduating class, 6 went into finance, 3 into computing and the other 9 into some form of engineering career, (Aerospace Engineering).
Both of those degrees should give you a good grounding in maths, but I don't recall anything I learned in my degree helping with the ATPL's.
With my interviews for sponsorship the contents of my degree never came up just the result, other than that it was personal qualities, aptitude tests, problem solving abilities etc.