Merge pull request #6249 from babatakao/fix_500_in_ruby19

Fix 500 error in Ruby 1.9.

app/views/shared/_file_hljs.html.haml

 %div.highlighted-data{class: user_color_scheme_class}
   .line-numbers
-    - blob.data.lines.size.times do |index|
+    - blob.data.lines.to_a.size.times do |index|
       - offset = defined?(first_line_number) ? first_line_number : 1
       - i = index + offset
       = link_to "#L#{i}", id: "L#{i}", rel: "#L#{i}" do