Fix handling of 0-dimension objects in jsonb_object()

When Who What
2016-03-03 11:54:13 Alexander Korotkov (smagen) Removed smagen from reviewers
2016-03-02 21:50:29 Alexander Korotkov (smagen) Added smagen as reviewer
2016-02-21 15:47:14 Andrew Dunstan (adunstan) Closed in commitfest 2016-03 with status: Committed
2016-02-12 02:39:07 Michael Paquier (michael-kun) Changed authors to Michael Paquier (michael-kun)
2016-02-12 02:39:07 Michael Paquier (michael-kun) Changed committer to adunstan
2016-02-12 02:38:56 Michael Paquier (michael-kun) Attached mail thread 20160208195207.2647.46863@wrigleys.postgresql.org
2016-02-12 02:38:56 Michael Paquier (michael-kun) Created patch record