Update RuboCop Performance to 1.11 (#35142).

git-svn-id: http://svn.redmine.org/redmine/trunk@20958 e93f8b46-1217-0410-a6f0-8f06a7374b81

Gemfile

@@ -93,7 +93,7 @@ group :test do
   gem 'webdrivers', '~> 4.4', require: false
   # RuboCop
   gem 'rubocop', '~> 1.13.0'
-  gem 'rubocop-performance', '~> 1.10.1'
+  gem 'rubocop-performance', '~> 1.11.0'
   gem 'rubocop-rails', '~> 2.9.0'
 end