Remove flawed noLinks handling for originUrls

Summary:
The original use of noLinks was to provide links to "kfileitem#"
targets, i.e. internal links only reachable when file indexing was
enabled (at Nepomuk times).

originUrls on the other hand are web/ftp server URLs, i.e.
independent from any local indexing.

Test Plan:

1. Add a originURL to a file:

$> setfattr -n user.xdg.origin.url -v "http://some.domain/"  test.txt

1. Make file readonly

With the change, the value label shown for originUrl ("Downloaded
from") stays the same

Reviewers: Baloo, ngraham, astippich

Reviewed By: Baloo, ngraham

Tags: Baloo

Differential Revision: https://phabricator.kde.org/D25238