Adapt failing tests for latest wsme version

Some error message has been changed with the 0.6.1 wsme version due to
the fixed default value handling in wsme.

See 9c8a033415606667eca915c863165e5f9021bccb in wsme repo

Change-Id: I93b7138dcef1fb9e9b0d71661c8bc5a6344adb35
Closes-bug: #1315926
(cherry picked from commit 64697095e5f486c7fe7208410f2c4a18573a7dc0)