res:dock:: fix trayicons won't be hidden on startup.

tower:https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/870b0343dc724bfab4f8b6cb11e2a272/
Change-Id: I1f3f72777cbc0c20b0bf8ec6669c1a769589f455