fixed milestone's unique constraint mapping
fixed milestone's unique constraint mapping

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