[ajax] fix the fix introduced in 3.9.1 to avoid duplicated loads: it cause some other errors since the browser may load the script *after* the server-response event is emited, causing pb if the script interact with this event

addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile