LP#1235474: fix failure of authority browse context menu to render

This patch fixes a situation where if an authority record that would
be brought up by the authority browse context menu in the MARC editor
lacks an 003 field, the context menu would not be rendered all, meaning
that the default context menu (e.g., cut/copy/paste/etc.) would be
displayed instead.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Dan Scott <dscott@laurentian.ca>