remove duplicate of add_user button id so the add user works. fixes #1271
remove duplicate of add_user button id so the add user works. fixes #1271

ndlib/scholarsphere,zhang4952/scholarsphere,jeremyf/sufia,zhang4952/scholarsphere,samvera/hyrax,zhang4952/scholarsphere,jeremyf/sufia,samvera/hyrax,ndlib/scholarsphere,samvera/hyrax,samvera/hyrax,ndlib/scholarsphere,zhang4952/scholarsphere