Issue installing plone.app.discussion = 2.4.20 on Plone 4

[SinghNav11]

Hello,

I am trying to install plone.app.discussion on Plone 4 with Python 2.7 and pinning the add-on's version to 2.4.20

Updated my buildout as below.
eggs =
plone.app.discussion

[versions]
plone.app.discussion = 2.4.20

Now trying to run a new buildout
sudo -u plone_buildout bin/buildout

I am getting below error messages:

Updating zeoserver.
Updating client1.
Download error on https://download.zope.org/ppix/: hostname 'download.zope.org' doesn't match 'vm06.plyp.com' -- Some packages may not be found!
Download error on https://download.zope.org/distribution/: hostname 'download.zope.org' doesn't match 'vm06.plyp.com' -- Some packages may not be found!
Getting distribution for 'plone.app.discussion==2.4.20'.
While:
Updating client1.
Getting distribution for 'plone.app.discussion==2.4.20'.
Error: Couldn't find a distribution for 'plone.app.discussion==2.4.20'.

Please help me I want install this version on Plone.app.discussion.
Thanks in advance