fix 当前用户没法查看posts 

需要判断`$this->params ` 不然会抛错
ErrorException [ 8 ]: Undefined index: id
fix 当前用户没法查看comments

需要判断`$this->params ` 不然会抛错
ErrorException [ 8 ]: Undefined index: id
Merge pull request #74 from youxiachai/patch-1

fix 当前用户没法查看post 和 comments