fix more cases where default_llm was used

Author: SamSaffron

lib/discord/bot/persona_replier.rb

@@ -13,7 +13,7 @@ def initialize(body)
           DiscourseAi::AiBot::Bot.as(
             Discourse.system_user,
             persona: @persona,
-            model: @persona.class.default_llm,
+            model: LlmModel.find(@persona.class.default_llm_id),
           )
         super(body)
       end

spec/jobs/regular/stream_discord_reply_spec.rb

@@ -13,9 +13,12 @@
     }.to_json.to_s
   end
 
+  fab!(:llm_model)
+  fab!(:persona) { Fabricate(:ai_persona, default_llm_id: llm_model.id) }
+
   before do
     SiteSetting.ai_discord_search_mode = "persona"
-    SiteSetting.ai_discord_search_persona = -1
+    SiteSetting.ai_discord_search_persona = persona.id
   end
 
   it "calls PersonaReplier when search mode is persona" do