This is always the version number when you compile it locally from a git clone instead of getting it from the pre-built paid sources. It will always say 1.x-dev when you compile yourself the way it’s set up right now unless you go in and edit some build files yourself. This means you can’t tell from 1.x-dev which version you have. The way you tell which version you have is at the point that you download the aseprite source.
Edit: It looks like you download the release zips instead of git cloning, the version number is set. so downloading from the releases page is a good way to avoid this problem.