workaround for regression in f14602cb34762f02ff483698b73ef963bdcb1da0

caused the WUI's welcome page to not display on client-only nodes due to
_node_key not being present.

This fixes it by falling back to displaying the old type of nodeid if the new
one is not present, as is the case on non-storage nodes.
Merge branch 'fix-clientonly' into merged