SiteAdmin: Fix that a deleted user doesn't leave project
SiteAdmin: Fix that a deleted user doesn't leave project

When a user is deleted by the Site administrator, the user leaves every
project automatically.

ChangsungKim/TestRepository01,yona-projects/yona,doortts/fork-yobi,brainagenet/yobi,yona-projects/yona,doortts/fork-yobi,violetag/demo,naver/yobi,ahb0327/yobi,oolso/yobi,doortts/fork-yobi,ihoneymon/yobi,bloodybear/yona,brainagenet/yobi,ChangsungKim/TestRepository01,oolso/yobi,ahb0327/yobi,doortts/forked-for-history,doortts/forked-for-history,naver/yobi,bloodybear/yona,doortts/fork-yobi,brainagenet/yobi,oolso/yobi,Limseunghwan/oss,violetag/demo,bloodybear/yona,naver/yobi,ihoneymon/yobi,yona-projects/yona,bloodybear/yona,doortts/forked-for-history,Limseunghwan/oss,Limseunghwan/oss,ihoneymon/yobi,yona-projects/yona,ahb0327/yobi