fix crash in length validator
fix crash in length validator

Signed-off-by: Sergei Ianovich <d8b1307a373c6b10457191cfe1c953896853372e@gmail.com>

sergeygaychuk/pcs-web,yanovich/pcs-web,yanovich/pcs-web,sergeygaychuk/pcs-web,sergeygaychuk/pcs-web,yanovich/pcs-web