I am currently on the 2nd year doing Computer Science and I will give you my opinion.
First of all, you should only follow programming/game engineering if you are absolutely sure you like coding and game development, because trust me, not everything works as l2j. You can become a l2j developer without even studying java, but studying on l2j code itself (see Tryskell, as he said he didn't have java knowledge when he begun and now he can code pretty much anything **in l2j**).
Another thing, don't expect your university to teach you everything you need, they will give you the basics and introduce you to programming but then you have to work your way up by reading online and practising a lot. Sure, there will be guidance on how to do that because of the projects you will be doing in your degree (for example this year I have to make an android application as a team project), but if you aim specifically for something you need to study on your own.
Finally, keep in mind that not everything in the course you will choose will be interesting and nice, there will be boring modules that you HAVE to attend and do coursework on them, as well as exams. I know this is quite obvious, but i'm telling you so that you can search more about each module before you choose the course, so that you don't end up enjoying only 1 or 2 out of 4 or 5 modules (happened to me last year).
If I were you, I would choose Software Engineering since it's a more generic degree and you can follow many different paths from it, so even if you change your opinion about game engineering, you can find a different job.
Good luck.