Configure error on CentOS 6

[patademahesh]

Hi,
Getting error while trying to build on centOS 6. Problem here is planex url is 404.

[xen@dev buildroot]$ ./configure
Looking for a file called ignore.CentOS.Final
Configuring RPM-based build
[sudo] password for xen:
Loaded plugins: fastestmirror
Setting up Install Process
Cannot open: https://xenserver.github.io/planex-release/rpm/el/planex-release-6-1.noarch.rpm. Skipping.
Error: Nothing to do

Thanks,
Mahesh