Adding new date rules on staff profile page bug

[Valentina R]

When adding date rules on the edit-user page for staff members, all the date rules change the ending time to the last added rule.

This can only be reproduced on the staff profile page (not on the product or WC settings pages).

Reported here: https://bookingwp.com/forums/topic/adding-a-rule-messes-up-dates-of-other-rules/

[Željan Topić]

Fixed with 4.4.9.4