Bug 426675: fix "index update with modified files" for a sub-directory

Change-Id: I3dad716cd11a464c97ee35fdabb8b9762238ccf3
Signed-off-by: Wei Li <wei.r.li@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/34434
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Cosmetics.