FIX: Use CDN for the discourse-internet-explorer

Previously the CDN was skipped because the assets were not in the proper
place to be uploaded.

lib/discourse.rb

@@ -194,6 +194,7 @@ module Discourse
         STDERR.puts "Could not activate #{p.metadata.name}, discourse does not meet required version (#{v})"
       end
     end
+    DiscourseEvent.trigger(:after_plugin_activation)
   end
 
   def self.disabled_plugin_names