The default (?) camera view is annoyingly slightly turned, see screenshot:
The way to temporarily fix this is to first rotate the camera 45 degrees (to either side) using ctrl + <-- or -->, and then to rotate it back (as far as it allows) using alt + --> or <-- (see screenshot):
However, I don't know how to fix it permanently, as after releasing the alt + arrow key the camera switches back to 45 degrees rotation, and there is no way to make it stick.
TL;DR: how do I make the default camera view straight (screenshot 2), and not slightly turned (screenshot 1)?

The way to temporarily fix this is to first rotate the camera 45 degrees (to either side) using ctrl + <-- or -->, and then to rotate it back (as far as it allows) using alt + --> or <-- (see screenshot):

However, I don't know how to fix it permanently, as after releasing the alt + arrow key the camera switches back to 45 degrees rotation, and there is no way to make it stick.
TL;DR: how do I make the default camera view straight (screenshot 2), and not slightly turned (screenshot 1)?