openvpn pam_google_authenticator.so error in centos 7

This is the short story: I was trying to implement google OTP authentication while connecting to openvpn, so that in addition to normal password you need to pass timed token generated by your mobile app. My OS was CentOS 7.

The problem was that it didn't work after following some instruction on the web. (like this one http://dillidba.blogspot.com/2017/02/install-openvpn-on-centos-with-google.html)

My openvpn log was showing this error:

Centos 7: uwsgi.sock failed (13: Permission denied) while connecting to upstream. How to fix.

In centos i had this issue in my nginx error.log:

uwsgi.sock failed (13: Permission denied) while connecting to upstream, client: ...

After searching a bit, I found that this is because of centos SELinux permissions.