/ip_addresses: fix 'missing attribute: model_id' error

Fix crash on /ip_addresses page when using the group by option. Caused
by attempting to include model_id in the data attributes when it isn't
present when using this option. Fix is to only include attributes that
are actually present.

app/models/ip_address.rb

@@ -42,4 +42,8 @@ class IpAddress < ApplicationRecord
   def readonly?
     true
   end
+
+  def html_data_attributes
+    super & attributes.keys.map(&:to_sym)
+  end
 end