Panic on exceeding max users during user creation

When on creation user count exceeds 32 (including system users) picodata fails with panic

Repro: !1493 (closed)

changed milestone to %25.1 - Datamart

added bug domain/acl labels

assigned to @e-ivkov

changed the description

mentioned in merge request !1509 (merged)

added triaged label

closed with merge request !1509 (merged)