Remove rs namespace from Redis keys

Superfluous, since the whole db should be RS only

spec/jobs/remote_storage_expire_authorization_job_spec.rb

@@ -20,7 +20,7 @@ RSpec.describe RemoteStorageExpireAuthorizationJob, type: :job do
   }
 
   it "removes the RS authorization from redis" do
-    redis_key = "rs:authorizations:#{@user.address}:#{@rs_authorization.token}"
+    redis_key = "authorizations:#{@user.cn}:#{@rs_authorization.token}"
     expect(redis.keys(redis_key)).to_not be_empty
 
     perform_enqueued_jobs { job }