Fix db8 recipe when it compiles with tests

Fix db8 recipe for correct spliting of release and debug packages when
db8 compiles with tests

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <msditanov@luxoft.com>

Change-Id: I1db211f5633524eb3f121170431418609165307f
Reviewed-on: http://g2g.palm.com/1605
Reviewed-by: Maksym Sditanov <msditanov@luxoft.com>
Tested-by: Maksym Sditanov <msditanov@luxoft.com>
Reviewed-by: Build Verification
Reviewed-by: Roger Stringer <roger.stringer@lge.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>