Refs #36757 - Avoid translations during startup

The model_name.human method actively translates, which can't be used
during start up and is not desired in this context.

Fixes: 827ee59 ("Fixes #30470 - Add DSL docs for smart proxy (theforeman#7846)")

app/models/smart_proxy.rb

@@ -196,7 +196,7 @@ def get_features
     end
   end
 
-  apipie :class, desc: "A class representing #{model_name.human} object" do
+  apipie :class, desc: "A class representing #{humanize_class_name} object" do
     name 'Smart Proxy'
     refs 'SmartProxy'
     sections only: %w[all additional]