Update postrm script to detect RHEL and not rm symlinks during upgrade
Update postrm script to detect RHEL and not rm symlinks during upgrade

During an upgrade, RPM runs the old package's post-uninstall script as the
last step. Replicate the solution from the same problem with Chef and Chef
Server (https://tickets.opscode.com/browse/CHEF-3022).

Signed-off-by: Robb Kidd <11cd4f9ba93acb67080ee4dad8d03929f9e64bf2@chef.io>

tas50/supermarket,robbkidd/supermarket,robbkidd/supermarket,chef/supermarket,juliandunn/supermarket,nellshamrell/supermarket,nellshamrell/supermarket,juliandunn/supermarket,tas50/supermarket,chef/supermarket,robbkidd/supermarket,juliandunn/supermarket,chef/supermarket,chef/supermarket,tas50/supermarket,robbkidd/supermarket,juliandunn/supermarket,nellshamrell/supermarket,nellshamrell/supermarket,tas50/supermarket,chef/supermarket