Warn the user that signed up with a social account and is trying to login with password but has none

If the user has signed up through a social network, they will have no password in the database. In such cases, when they try to login, we should warn them "hey, we know you but you still have no password. You should use the 'forgot password' link down below or login through one of the following networks we have on your file: xxx, yyy".