1PX disappeared after compilation

[pigjane]

new CleanCSS({
  level: 2
}).minify('p{border:1PX solid #eee}').styles;

the above code should output p{border:1PX solid #eee}

but actually output p{border:solid #eee}

[jakubpawlowicz]

Fixed on main branch, soon to be released as per discussion in #1135