Upload limit increased

[Lia]

Previously files up to 1MB were allowed (as was the case on the former forum) however I've increased this to 2MB since downscaling an image to fit under that threshold was a bit brutal on image quality.

This was a default limitation of the web server responsible for interpreting inbound traffic and delegating it to the website more so than NodeBB itself. Quick change in the config and a reload is all that took.

If you'd like this raising a little more let me know :)