Fix the image file that contains non-ascii character is not displayed

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.14.0 (unreleased)
+  - Fix the image file that contains non-ascii character is not displayed(Hiroyuki Sato)
   - Fix URL used for refreshing notes if relative_url is present (Bartłomiej Święcki)
   - Fix Error 500 when browsing projects with no HEAD (Stan Hu)
   - Fix full screen mode for snippet comments (Daniel Gerhardt)

lib/gitlab/markdown/relative_link_filter.rb

@@ -98,9 +98,10 @@ module Gitlab
       #
       # Returns a String
       def path_type(path)
-        if repository.tree(current_sha, path).entries.any?
+        unescaped_path = Addressable::URI.unescape(path)
+        if repository.tree(current_sha, unescaped_path).entries.any?
           'tree'
-        elsif repository.blob_at(current_sha, path).try(:image?)
+        elsif repository.blob_at(current_sha, unescaped_path).try(:image?)
           'raw'
         else
           'blob'