There is now a new option where you can change that, but you have to press Esc, go to the Options, and on the System tab, you'll find a new slider on the right side of the panel called "External Field of View". If your external camera is all zoomed out, giving you the Fish Eye effect, it means this Field of View slider is tuned all the way up to 140°. Change that to something around 60~70 and you'll get the old default angle.
I also hated this change. It's simply unecessary, since we've always had the NumPad hotkey combos to control that.
WilliamLink's post in Multiplayer external view fishbowl was marked as the answer