Multibyte support for file upload(Web UI).

When a file of the file name of Japanese (画像.png) was added in WebUI in GitLab, an error occurred.

So when the regular expression was changed as follows, it could be added.

--- regex.rb.org        2016-05-09 14:27:15.937753205 +0900
+++ regex.rb    2016-05-09 14:29:33.357748291 +0900
@@ -44,7 +44,7 @@


     def file_name_regex
-      @file_name_regex ||= /\A[a-zA-Z0-9_\-\.\@]*\z/.freeze
+      @file_name_regex ||= /\A[[:word:]_\-\.\@]*\z/.freeze
     end

     def file_name_regex_message
@@ -52,7 +52,7 @@
     end

     def file_path_regex
-      @file_path_regex ||= /\A[a-zA-Z0-9_\-\.\/\@]*\z/.freeze
+      @file_path_regex ||= /\A[[:word:]_\-\.\/\@]*\z/.freeze
     end

     def file_path_regex_message