fix sign_off handling in multi image edit modal
fix sign_off handling in multi image edit modal

SDANSA-477

petrjasek/superdesk-client-core,petrjasek/superdesk-client-core,superdesk/superdesk-client-core,superdesk/superdesk-client-core,petrjasek/superdesk-client-core,superdesk/superdesk-client-core,petrjasek/superdesk-client-core,superdesk/superdesk-client-core,petrjasek/superdesk-client-core,superdesk/superdesk-client-core