After the report rename made --logs-global-vector-image return the raw
stored value (empty when unset) and split --logs-computed-vector-image
out as the default-resolved key, the (logs:report)
vector-global-image and vector-global-networks raw test still pinned
assert_output_exists on the raw key in the unset state. The raw key is
correctly empty after dokku logs:set --global vector-image runs, and
the bundled vector image default is exposed via the computed key now.
3d3c95545c