FIX: Switch discobot to pull avatar from gravatar.

plugins/discourse-narrative-bot/plugin.rb

@@ -55,6 +55,7 @@ after_initialize do
 
   module ::DiscourseNarrativeBot
     PLUGIN_NAME = "discourse-narrative-bot".freeze
+    BOT_USER_ID = -2
 
     class Engine < ::Rails::Engine
       engine_name PLUGIN_NAME
@@ -271,4 +272,9 @@ after_initialize do
       end
     end
   end
+
+  UserAvatar.register_custom_user_gravatar_email_hash(
+    DiscourseNarrativeBot::BOT_USER_ID,
+    "discobot@discourse.org"
+  )
 end