webos-image: libpbnjson=29

:Release Notes:
Fix 'required' keyword in JSON schemas.

:Detailed Notes:
submissions/28..submissions/29
caa890f Fix JSON schema 'required' keyword parsing

:Testing Performed:
MiniBAT

:QA Notes:

:Issues Addressed:
[ANG-1452] pbnjson: Ensure the property "required" isn't an empty array
[ANG-1962] CCC: libpbnjson=29

Open-webOS-DCO-1.0-Signed-off-by: Alexandr Smoktal <alexandr.smoktal@lge.com>

Change-Id: Icda71c78886e4e5acb9a858c59462e1b8d8af8f5
Reviewed-on: https://g2g.palm.com/4719
Reviewed-by: DCO Verification
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Alexandr Smoktal <alexandr.smoktal@lge.com>
Tested-by: Alexandr Smoktal <alexandr.smoktal@lge.com>
Reviewed-by: Alexander Irhin <alexander.irhin@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>