Windows: staged update fails if Meek is enabled

On Windows, if Meek is enabled, the updater fails while trying to copy files to the staged "update applied" directory. Failure occurs because the file Browser/TorBrowser/Data/Browser/profile.meek-http-helper/parent.lock is in use. The updater will fallback to an unstaged update and users will be prompted to restart to apply the update. This works but a large updated/ directory is left behind which will not be deleted until another update is staged.

We can fix this problem by skipping this parent.lock file inside the updater when copying files.