* Fixes issue in FailedLogin model:
- fix data-model to remove nested 'attempted.attempted'
- migrate existing data to remove nested field
* Also, avoid setting dt_now() in model as that results in fixed date for
all objects:
- update FailedLogin to update 'attempted' date on every attempt
- also update PageNote object to set date in constructor
* Update text for too many logins to make it clear it is set only if its a
valid email
* fixes#2001
