mount: fixed mounting of directories w/symlinks over WebDAV (#1358)
mount: fixed mounting of directories w/symlinks over WebDAV (#1358)

Directories containing symlinks could not be mounted on Windows and
were failing with 'invalid parameter'.

This change skips those entries and emits a warning to the console.

Symlinks appear to be unsupported in WebDAV at the protocol level
and servers usually follow symlinks server-side, which is not
feasible for Kopia. In the future we may be able to do more here, but
for now it's better to not show symlinks than not show anything.

Huge thanks to Joe Occhipinti for his help getting to the bottom of this
issue.
kopia/kopia,kopia/kopia,kopia/kopia,kopia/kopia