Use nokogiri 1.9 for Ruby 2.2 (#30241).

git-svn-id: http://svn.redmine.org/redmine/trunk@17778 e93f8b46-1217-0410-a6f0-8f06a7374b81

Gemfile

@@ -14,7 +14,7 @@ gem "mimemagic"
 gem "mail", "~> 2.7.1"
 gem "csv", "~> 3.0.1" if RUBY_VERSION >= "2.3" && RUBY_VERSION < "2.6"
 
-gem "nokogiri", "~> 1.10.0"
+gem "nokogiri", (RUBY_VERSION >= "2.3" ? "~> 1.10.0" : "~> 1.9.1")
 gem "i18n", "~> 0.7.0"
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem