Any engineering degree, even if it's in a broad discipline like mechanical, chemical or civil engineering, will not only give you a respectable and versatile qualification for backup but will also teach you transferable skills which will eventually make you a better pilot and more efficient all-round. Being able to research a problem independently or as part of a team, propose a solution to it and present it appropriately is a major part of many jobs, not just of airline flying. The same goes for time management, processing large volumes of information, adapting to a new and diverse environment, getting your work-life balance right and whatnot else that you will naturally learn at uni and will never learn solely by drilling through ATPL question banks. The latter reminds me of the proverbial cadet who was asked a simple aerodynamics question in an airline interview and replied with "What are the options?". Don't be that person.
And, to reiterate on what some members rightly said above - even if you're doing an aviation degree, never forget that it's an entirely different cup of tea than flight training. If you go in with the expectations of doing a three-year course in "flying with partying", you will be frustrated AF by the end of semester one. Rather than that, treat it as an opportunity to expand your skills and knowledge and as a broad base, allowing you to easily specialize in flying at a later time. And, of course, get the most of it, have a lot of fun and build some lifelong friendships and memories on the way.