Do not reload the filelist on first open

Fixes: #4644

Without this patch the filelist would always reload. However since not
all the correct data was set yet it would often:

1. fireoff a propfind to ../webdav/
2. fireoff a propfind to ../webdav/<PATH>

When just opening the file list those are the same so the result is just
fine. However if opening a direct link it means that there is a race
condition on which finishes first.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>