Description of problem:
I had existing networks in 7.3 and they were displayed properly in the network topology page in horizon. After the upgrade to 8.0 the same page in horizon only shows the buttons at the top (to create a network/router/instance) but the canvas that's supposed to display the topology in the new format is empty.


Version-Release number of selected component (if applicable):
python-tripleoclient-0.3.4-1.el7ost.noarch


How reproducible:
unknown because I'm a bit stuck on my new upgrade attempts, but I'm sure this will happen every time


Steps to Reproduce:
1. Install osp with director 7.3
2. Populate the overcloud with networks and instances
3. Upgrade the undercloud and overcloud to 8.0
4. Log in to horizon and see if there is anything in the network topology


Actual results:
The network topology page is blank