private void createLocalSessionIfMissing(ApplicationId applicationId, long sessionId) {
        Tenant tenant = applicationRepository.getTenant(applicationId);
        SessionRepository sessionRepository = tenant.getSessionRepository();
        if (sessionRepository.getLocalSession(sessionId) == null)
            sessionRepository.createLocalSessionFromDistributedApplicationPackage(sessionId);
    }
Verifies that all active sessions has an application package on local disk.
If not, the package is downloaded with file distribution. This can happen e.g.
if a config server is down when the application is deployed. This maintainer should only be run
if there is more than 1 config server

@author gjoranv
configserver/src/main/java/com/yahoo/vespa/config/server/maintenance/ApplicationPackageMaintainer.java