scheduler: Fix cleaning jobs by loading times when needed

Currently if we load jobs from job.cache, we don't set correct times for history_time and file_time, resulting them in being 0 and the jobs avoids the cleanup by cupsd when needed, leading into eating up memory space.

It happens because none of the functions which set those job members are not called - cupsdSetJobState() is used when changing job states, cupsdUpdateJobs() during partial reload and cupsdLoadJob() is guarded by condition in load_job_cache().

The fix is to change conditional in load_job_cache() which will cause loading of the job if cupsd is set to clean up job history, or if cupsd should clean up job files and the job still has some.