OSPF: Reference_bandwidth is copied into vrfs, but some of the templates don't reference it there

[jbemmel]

netlab/netsim/modules/ospf.py

Line 58 in 82df118

* OSPF area, reference_bandwidth, and router_id are copied into vrfs.x.ospf if needed

I was working on the Dell OS10 VRF template, adding a fix for reference_bandwidth in case of VRFs - but noticed that many of the other templates have the same issue.

I don't see a good use case for having reference_bandwidth set to a different value at the VRF level, so we could also decide to only have it globally. But since it's copied, it should be referenced