Unhelpful Upgrade Warning

[wxtim]

In the case where a workflow has the following config

# part of a suite.rc

[scheduling]
  [[dependencies]]
    graph = foo

and

$ cylc validate
WARNING - deprecated graph items were automatically upgraded in "workflow definition":
     * (8.0.0) [scheduling][dependencies][X]graph -> [scheduling][graph]X - for X in:
           R1
# ...

But without X, this doesn't make much sense.