res_pjsip_config_wizard: Fix leaks and add check for malloc failure.

wizard_apply_handler():
- Free host if we fail to add it to the vector.

wizard_mapped_observer():
- Check for otw allocation failure.
- Free otw if we fail to add it to the vector.

Change-Id: Ib5d3bcabbd9c24dd8a3c9cc692a794a5f60243ad