User with invalid date value will break /users/expire/timer API

Overview:
A user record that has an invalid date value in one of the datetime properties will cause the /users/expire/timer API call to fail with an NPE. The module will not close the connection, so over time the number of connections between Okapi and mod-users will reach the 1000-connection limit and the FOLIO system will become unresponsive. Also, of course, no users will ever actually be expired, because the API call will never complete.

Steps to Reproduce:

• create a user create a user with the birth date 0000-01-01 (UIU-2651)
• give the user an expiration date that will cause the user expiration timer to try to act on the user

Expected Results:
The user record will be set to "active": false

Actual Results:
The /users/expire/timer API call never returns, leaving the connection open. The mod-users log shows an NPE. The user record is not updated by the timer.

Interested parties:
ggoldner