Thanks guys for your answers..
I missed to update my answer, I fixed that issue in an easy way.
Solution is first run unstack.sh and then run stack.sh once more. It will do the necessary fix. Since I haven't made much progress with Devstack after installation it makes me more confident to run stack.sh
For the second time when you run stack.sh its not needed to connect to internet, So my issue is fixed.
Feel free to share your thoughts on this.