[WEB-882] Skin upload API max file size is slightly higher than maximum in profile settings

The bug

The maximum file size of skins was set to 16384 for the page https://minecraft.net/en-us/profile/?ref=bm. However, apparently this was only hardcoded in the JavaScript code of the page:

validateSkinFile: function(e) {
    return new r.Promise(function(t, n) {
        var o;
        if ("png" !== e.name.match(/\.([^\.]+)$/)[1].toLowerCase())
            return void n(new Error("File is not an .png"));
        if (e.size > 16384)
            return void n(new Error("File is too large"));
...

The API still uses 24576 bytes as maximum value:

{"error":"IllegalArgumentException","errorMessage":"Max allowed size is 24576 bytes"}