GET empty data doesn't return error messages

See e.g.
Test_Scenario_17_precondition = {
'uri': '/config/opendaylight-inventory:nodes/node/id17/table/17',
'headers':

,
'expected_status': 404,
'expected': '''
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<errors
xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
<error>
<error-type>application</error-type>
<error-tag>data-missing</error-tag>
<error-message>No data was found.</error-message>
</error>
</errors>
'''
}

No error message is received.

Expected result:
In received <rpc-error> must be according RFC 6241 Appendix A page 78
error-tag: data-missing
error-type: application
error-severity: error
Description: Request could not be completed because the relevant
data model content does not exist. For example,
a "delete" operation was attempted on
data that does not exist.

Release Candidate version
0.2.0-Helium-RC1-6-v201409220013