cli: unclear error message when using unsupported 2 levels attribute(#949642)

unclear error message (error: type "%s" does not exist.) when
using unsupported 2 levels attribute.

when using unsupported 2 levels attribute (both are not supported)
the returned error is not user friendly

Change-Id: Ia96c23ad2462d2d4f2cbe0a4d64996eae8f40854
Bug-Url: https://bugzilla.redhat.com/949642
Signed-off-by: Ravi Nori <rnori@redhat.com>