fdo#81304 don't parse file name as part of URL

... because the name is not URL-encoded at this point, so parsing it as
a part of the URL will interpret special characters, e.g. #.

Change-Id: I780baed1753e9674d835dc296d31c088b67d8ba7
(cherry picked from commit f3d7734af45f30a87d6de76aa3de7593d541bdc8)
Reviewed-on: https://gerrit.libreoffice.org/10295
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>