[FIX] website_blog:redirection 301 instead of 302 to new blog

-Create a second blog
-Move one post to this second blog
-Access the post with the url from the first blog

Before this commit:
You will get redirected to the new url with a code 302 (temporary).

After this commit:
You will get redirected to the new url with the code to 301 (permanent).

OPW-2059194

closes odoo/odoo#36161

Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

addons/website_blog/controllers/main.py

@@ -230,7 +230,7 @@ class WebsiteBlog(http.Controller):
         blog_url = QueryURL('', ['blog', 'tag'], blog=blog_post.blog_id, tag=tag, date_begin=date_begin, date_end=date_end)
 
         if not blog_post.blog_id.id == blog.id:
-            return request.redirect("/blog/%s/post/%s" % (slug(blog_post.blog_id), slug(blog_post)))
+            return request.redirect("/blog/%s/post/%s" % (slug(blog_post.blog_id), slug(blog_post)), code=301)
 
         tags = request.env['blog.tag'].search([])