Allow remember token to be stored in the database with a default value of the empty string or 0 or something else that is not null, if a user so chooses.

Checking is_null would make it so the user would not be remembered after the first login if you have the remember_token field default in the database set to anything but null.
Delete existing password reminder tokens in database.
Merge branch '4.2'
Fix type hints.
Missing NotFoundHttpException used

Method getReset() uses NotFoundHttpException but file never uses it.
Merge pull request #5302 from rickywiens/4.2

[4.2] Allow remember token to be stored in the database with a non-null default
Merge branch '4.2'