[web/data] fix treeview regression (closes #3526466)
Changeset 68cde7431c2c "[js] remove 3.9 bw compat (where apparently
unused)" removed the use of form.callback from loadxhtml, which treeview
relied on. Update to add a callback on the loadxhtml return value
instead.
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
"""