Fix will_paginate crash when Meilisearch disabled

When Meilisearch is disabled, NullObject is passed to will_paginate when
it expects integers.

lib/meilisearch/rails/pagination/will_paginate.rb

@@ -10,6 +10,10 @@ module Rails
     module Pagination
       class WillPaginate
         def self.create(results, total_hits, options = {})
+          total_hits = 0 if Utilities.null_object?(total_hits)
+          options[:page] = 1 if Utilities.null_object?(options[:page])
+          options[:per_page] = 1 if Utilities.null_object?(options[:per_page])
+
           ::WillPaginate::Collection.create(options[:page], options[:per_page], total_hits) do |pager|
             pager.replace results
           end

lib/meilisearch/rails/utilities.rb

@@ -56,6 +56,10 @@ def sequel_model?(model_class)
           defined?(::Sequel::Model) && model_class < Sequel::Model
         end
 
+        def null_object?(obj)
+          obj.is_a? NullObject
+        end
+
         private
 
         def constraint_passes?(record, constraint)