Bad URL for gravatar in the kanban view

[Christophe Combelles]

Gravatars never display in the kanban view.

the reason is :
openerp/addons/web_kanban/static/src/js/kanban.js:555: return 'http://www.gravatar.com/avatar/' + email_md5 + '.png?s=' + size + '&d=' + default_;

Just fix by replacing '.png?s=' with '?s='

[Carlos Vásquez (ClearCorp) (cv.clearcorp)]

Actually, the .png is not wrong.

If you don't specify the extension, Gravatar defaults to jpeg, which is not optimal for this use.

But one thing that is not working is the cache timeout for the identicon option. Gravatar has a bug on this.

To reproduce it:
- Configure an user with an email account that doesn't have any gravatar configured
- Go to the tasks kanban view in OpenERP and create a new task for this user
- You will see a classical generated gravatar identicon
- Then go to gravatar.com and configure a new image for this user
- Go back to tasks kanban view, you will see that the gravatar is the same, even refreshing and clearing the browser cache. This is normal for a few hours due to gravatar.com cache
- You can wait even several days, but the gravatar won't refresh, we tried several times with 3-4 days and nothing. This is a bug in gravatar cache

To avoid this a simple workaround can be integrated in the code to force a new image every day. That way we don't force the cache and refreshing gravatars only takes 24 hours max.

I am doing a merge proposal with this code right now.