Get cidr/mask_bits according to ip_version in resource_setup

This is to get cidr/mask_bits according to ip_version in
resource_setup in network/base.py, to avoid the similar error as
in I8611429892f5d3f582b9a40ef8b418f5ca89c0a7.

Change-Id: Ie264ac7ee03bbc49592ce12b0753a50075f8517d
5 files changed