Comment 4 for bug 1259562

Yeah, calling DeleteUser would help, though it's not symmetrical since we didn't call AddUser in the first place. There's a bunch of ways where accounts could disappear without accounts service being explicitly notified. The most reliable method would be for it to purge it's cache when it detects this.

The attached patch will probably fix this (not tested) since A-S already scans the cache directory on startup.