fix petpage export item name filtering

The "Abominable Snowball Winter Onesie" can get blocked for including the string " On".
So, we meant to filter that to " O<b></b>n" so that the filter wouldn't return that false
positive on an XSS attempt, but were accidentally filtering it to " o&lt;b&gt;&lt;/b&;gtn".
Fixed :)

app/helpers/closet_hangers_helper.rb

@@ -77,7 +77,7 @@ module ClosetHangersHelper
   end
 
   def petpage_item_name(item)
-    item.name.gsub(/ on/i, ' o<b></b>n')
+    item.name.gsub(/ On/i, ' O<b></b>n').html_safe
   end
 
   PETPAGE_IMAGE_URL_BLACKLIST = %w(window. ondrop)