Fix 0.33.0 year in CHANGELOG.md

[strohel]

@est31 thanks for cutting the release!

Could you please also push a git tag from 0.33 and maybe also create a GitHub release from it? Thanks! CC @bschwind.

[est31]

tag created. I'm not sure a github release is useful.

[strohel]

@est31 thank you! BTW I'm not seeing the tag in https://github.com/glium/glium/tags, you may need to push it using git push origin v0.33.0.

The only thing the GitHub release is useful is perhaps showing up-to-date version in the Releases section of the GitHub sidebar:

But that's really minor.

[est31]

I actually pushed it to origin (the fork under my personal account), the issue was that I had to push it to upstream which is how I call the glium/glium remote. Pushed it also to upstream. Thanks for checking!