[REFACTOR] removed compatibility code from FileZipper

The FileSubmitter class now compress the LOG file by its own.

Change-Id: I07784e26a21dc2eaac22cdb38f86ec229c928626
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1662
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>