Changes of the SEO url of blog.blog in frontend won’t be applied

[rruebner]

Problem

If you change the SEO url of blog.blog in frontend the changes won’t be applied in the view and bot in the menu.

Steps to reproduce

• create a new database with demo data
• install the website_seo_blog module
• go to a blog (blog.blog) page in the frontend, open the promote panel, change the SEO url and save:
  • the promote panel is closed
  • you see a 404 page
  • the SEO url is not saved in the view
  • the SEO url is not saved in the menu
• tested in the latest odoo v9

Expected behaviour

• the SEO url for blog pages should be saved in the view and the menu

@rruebner Hi, would you please review the changes.