Whether or not a shift needs a user_id will be dependant on the scheduling mode of the position. Remove validator fromm model.
Whether or not a shift needs a user_id will be dependant on the scheduling mode of the position. Remove validator fromm model.

Signed-off-by: Max Fierke <0706025b2bbcec1ed8d64822f4eccd96314938d0@maxfierke.com>

OfficeStack/OpenSkedge2