CSIT: Unify path for robot plugin

CSIT: Unify path for robot plugin

+ We are trying to remove duplicates from logs.fd.io.
+ The unified path for logs is "archives" directory.
 - Except per-patch job, to be fixed later.
+ So, tell Robot plugin to get outputs from there.
 + Use quotes around the value.
- This may break some old CSIT branches.
 + If yes, we will fix the CSIT code part (not ci-management).
- Not touching inactive projects.

Change-Id: I55f974ab27a2085690396db5b448978016c98684
Signed-off-by: Vratko Polak <vrpolak@cisco.com>