Change resolution by WebUI

[LLKoder]

Im not sure my case is bug so I need community opinion.
I run SD in img2img mode. Load image and set resolution.
Click generate. And I see SD change my resolution.
Input resolution: 540x960
Output resolution: 536x960
Why did the changes happen?

[missionfloyd]

It's because 540 isn't a multiple of 8.