deposit: ckeditor sanity check
deposit: ckeditor sanity check

* Avoid error if deposit form is not using ckeditor in any field.

Signed-off-by: Javier Martin Montull <ea6b80e26c65acc242d8916fb6eefa01b123cb69@cern.ch>

inveniosoftware/invenio-deposit,inveniosoftware/invenio-deposit,inveniosoftware/invenio-deposit,inveniosoftware/invenio-deposit