Do not delete optional value for fields not set by the call

The same view may have different set of fields if it is extended conditionally.

Closes #13758
(grafted from 826ac4da1e20acd1e1b5aec3c3aaa00f04cdc81b)

--HG--
branch : 7.0

trytond/trytond/ir/ui/view.py

@@ -501,6 +501,7 @@ class ViewTreeOptional(ModelSQL, ModelView):
         records = cls.search([
                 ('view_id', '=', view_id),
                 ('user', '=', user),
+                ('field', 'in', list(fields)),
                 ])
         cls.delete(records)
         to_create = []