lava_rpc_connector.py: block_wait_for_jobs: Don't requery finished jobs

Previously, all finished jobs were re-queried from LAVA again and again,
which put undue load on the LAVA server and likely slowed down the build
itself.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I58a7eb2735c22df9d306b885977eb85e3b17f7eb
1 file changed