Fix cancel action on deletion confirmation form Currently crashed with RequestError: invalid action '__action_cancel'. It's broken as of https://hg.logilab.org/master/cubicweb/rev/cb217b2b3 This fix is similar as the one done in https://hg.logilab.org/master/cubicweb/rev/9f1c89e7426d Closes #13521493

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