Fix #3031: Auto-assign sub-task to task owner
Fix #3031: Auto-assign sub-task to task owner

oliviermaridat/kanboard,renothing/kanboard,filhocf/kanboard,libin/kanboard,Busfreak/kanboard,oliviermaridat/kanboard,Busfreak/kanboard,patoi/kanboard,stinnux/kanboard,patoi/kanboard,kanboard/kanboard,kanboard/kanboard,kanboard/kanboard,filhocf/kanboard,renothing/kanboard,thylo/kanboard,thylo/kanboard,renothing/kanboard,filhocf/kanboard,libin/kanboard,stinnux/kanboard,stinnux/kanboard,fguillot/kanboard,fguillot/kanboard,thylo/kanboard,BlueTeck/kanboard,Busfreak/kanboard,oliviermaridat/kanboard,patoi/kanboard,BlueTeck/kanboard,fguillot/kanboard,BlueTeck/kanboard