Use production? over == "production"

In rails#46656 we disable the IRB autocompletion if it's production. The
original PR used `== "production"` but it's cleaner if we use the
`production?` helper instead.

Author: eileencodes

railties/lib/rails/commands/console/console_command.rb

@@ -39,7 +39,7 @@ def initialize(app, options = {})
       if @console == IRB
         IRB::WorkSpace.prepend(BacktraceCleaner)
 
-        if Rails.env == "production"
+        if Rails.env.production?
           ENV["IRB_USE_AUTOCOMPLETE"] ||= "false"
         end
       end