Newer versions of Linux increasingly are migrating from old-style System V init scripts to the systemd management framework for services. This framework introduces various changes that deployers may need to be aware of. While some basic compatibility is provided on most systems so that the usual service control commands will work, the RPM packages on these platforms do not install a standard init script or a sysconfig script.
Instead, the package includes a read-only "unit" file installed to /usr/lib/systemd/system/shibd.service that describes how to manage the service. Do not modify this file, as it will be replaced during upgrades.
If you want to modify anything in the file, the best way to do this is to create a file named /etc/systemd/system/shibd.service.d/shibd.conf and include any overridden lines you want to merge into the file. You can name the file itself anything that ends in the "conf" extension, but do not create that directory and leave it empty.