Fix Rubocop MFA offense

Author: n-rodriguez

ajax-datatables-rails.gemspec

@@ -13,10 +13,11 @@ Gem::Specification.new do |s|
   s.description = "A wrapper around datatable's ajax methods that allow synchronization with server-side pagination in a rails app"
   s.license     = 'MIT'
   s.metadata    = {
-    'homepage_uri'    => 'https://github.com/jbox-web/ajax-datatables-rails',
-    'changelog_uri'   => 'https://github.com/jbox-web/ajax-datatables-rails/blob/master/CHANGELOG.md',
-    'source_code_uri' => 'https://github.com/jbox-web/ajax-datatables-rails',
-    'bug_tracker_uri' => 'https://github.com/jbox-web/ajax-datatables-rails/issues',
+    'homepage_uri'          => 'https://github.com/jbox-web/ajax-datatables-rails',
+    'changelog_uri'         => 'https://github.com/jbox-web/ajax-datatables-rails/blob/master/CHANGELOG.md',
+    'source_code_uri'       => 'https://github.com/jbox-web/ajax-datatables-rails',
+    'bug_tracker_uri'       => 'https://github.com/jbox-web/ajax-datatables-rails/issues',
+    'rubygems_mfa_required' => 'true',
   }
 
   s.required_ruby_version = '>= 3.0.0'