path completion: no completions for resources same folder

[aeschli]

Testing #44460

Version 1.21.0-insider
Commit 9a04587
Date 2018-03-01T06:47:39.037Z

• create foo.html, bar.html in a folder
• in `foo.html' have

<a href="b"

and do code completion after b.

-> should show bar.html as a proposal