SSH Quick Install: incorrect or header missing

When reviewing the 'SSH Quick Install' instructions here: http://docs.mybb.com/1.8/install/ I ran across an issue running wget and curl I believe it may be due to a missing header on the server.

z@zap:~ % wget --content-disposition https://www.mybb.com/download/latest -O mybb.zip
--2016-07-06 22:16:16--  https://www.mybb.com/download/latest
Resolving www.mybb.com (www.mybb.com)... 104.24.8.55, 104.24.9.55, 2400:cb00:2048:1::6818:937, ...
Connecting to www.mybb.com (www.mybb.com)|104.24.8.55|:443... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: http://www.mybb.com/download/latest/ [following]
--2016-07-06 22:16:16--  http://www.mybb.com/download/latest/
Connecting to www.mybb.com (www.mybb.com)|104.24.8.55|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Saving to: ‘mybb.zip’

    [ <=>                                                                         ] 503         --.-K/s   in 0s      

2016-07-06 22:16:16 (158 MB/s) - ‘mybb.zip’ saved [503]
z@zap:~ % unzip mybb.zip
Archive:  mybb.zip
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of mybb.zip or
        mybb.zip.zip, and cannot find mybb.zip.ZIP, period.

Outputting the contents of the file, I see HTML:

z@zap:~ % cat mybb.zip
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
    <head>
        <meta content="text/html; charset=UTF-8" http-equiv="content-type" />
        <meta http-equiv="refresh" content="0; url=https://resources.mybb.com/downloads/mybb_1807.zip">
        <link rel="canonical" href="https://resources.mybb.com/downloads/mybb_1807.zip" />
        <title>Redirecting</title>
    </head>
    <body>
    </body>
</html>%

Referencing the wget man page for the flag:

--content-disposition
           If this is set to on, experimental (not fully-functional) support for "Content-Disposition" headers is enabled. This can currently result in extra round-trips to the server for a "HEAD" request, and is known to suffer from a few bugs, which is why it is not currently enabled by
 default.

           This option is useful for some file-downloading CGI programs that use "Content-Disposition" headers to describe what the name of a downloaded file should be.

Cross reference the response headers:

z@zap:~ % curl -I https://www.mybb.com/download/latest |grep -i "content-disposition"
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0

Content-Disposition does not appear to be present, which could be the cause of downloading HTML using wget or curl.