Hey there.
Well..... I'd guess that studying a degree such as engineering etc. would not only indicate to prospective employers that you've got a reasonable talent for solid academic study but also that you've probably got a much sounder knowledge of your aircraft systems over and above the ATPL exams.
Also should something irritating happen (i.e. legs fall off) you have an excellent backup career if you really can't go on with flying.
I can't see any way how airlines can take your degree as something to negatively affect your application!
Good luck mate
Andy