[FIX] web: regard the view_list has valid if not yet loaded

This fix is related to df845940ed52040ef92b1b5759306c556fa38e66

Fixes #3469
[MERGE] forward port of branch 7.0 up to 9a37e5a
[MERGE] forward port of branch saas-3 up to c11451c
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-linux64