user/profile: Fix a server error by an empty daysAgo cookie
user/profile: Fix a server error by an empty daysAgo cookie

NumberFormatException was thrown when someone access a user page with an
empty daysAgo cookie.

I don't know when the cookie has a empty value.

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