At RPM update use new (changed) config file and save edited one on disk

At the moment the RPM spec file is set to keep an edited scdaq.conf file and name a new one from the RPM as scdaq.conf.rpmnew. We should change this to ensure that new configuration options are set. The desired behaviour is that we use scdaq.conf from the RPM if it has been changed in the new package and rename the old config file to scdaq.conf.rpmsave.