Login should say "Invalid email or password" instead of "invalid password" or "account not found"

Small enhancement request:

The website login should use an error message that does not indicate which of user id (email) or password was invalid. This is one of those “OWASP top 10” issues that prevents information leakage. An attacker could use the fact that a specific failure happens to discover valid electric imp account names.

Form that exhibits this behavior is at: https://plan.electricimp.com/login
Discussion of the issue is at: https://www.owasp.org/index.php/Authentication_Cheat_Sheet#Authentication_and_Error_Messages