What is accountsd and why does it want to use the "login" keychain?
Open Keychain Access, which can be found in /Applications/Utilities. 

Then select Keychain First Aid under Keychain Access.

Enter your password and click to Verify (this is important to find out how is making the problem just in case it comes up again).

If it shows Errors use the Repair function.

In my case it looked like this before the repair.

It found one error and it was fixed after the repair.