Only check if place url is mount point once during polish event.

Only check if place url is mount point once during polish event.

The capacity bars will no longer update when capacity changes. It only
checks the size on init.

Updating during polish event is only a temporarily solution just to
draft code flow for seperating logic from painting. Eventually this
logic update should be in a worker thread detached from blocking the
rendering thread that blocks launching the dolphin window.