Do not delete tokens after job completion.
Do not delete tokens after job completion.

With the latest change to reuse tokens if available we shouldn't delete tokens
at the end of job completion.

Change-Id: I8e28b556d6840b14c4d24cad7a96767ac070c330

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server