in `view_pivot.js`,
the method `view_loading` must wait the `self.fields` variable
to be defined before working properly.
This `self.fields` variable is filled in the `prepare_fields` method,
which is called in the `start` method, through a deferred named
`load_fields`.
`view_loading` is called in `start`, in `views.js`.
Therefore, in the overriden method `start` of `view_pivot.js`,
the call to `_super`, calling the `start` of `views.js`, must wait for
the `load_fields` deferred to be resolved.
Otherwise, the `self.fields` variable, mentioned above, won't be
filled in time.
opw-660153
Denis Ledoux
c9acaa428c