[FIX] account: fix $.when(defs) in reconciliation widget

Introduced by: https://github.com/odoo/odoo/commit/b0a29c9bad4fb9180ddcdae80529e244c6b61d49

Suppose def1, def2, def3, three deferred.
$.when(def1, def2, def3) is ok
$.when([def1, def2, def3]) is not ok
$.when.apply($, [def1, def2, def3]) is ok

closes odoo/odoo#27513