change default llm, logger messages

app.py

@@ -56,12 +56,12 @@ def bot(history, chunk_table, embedding_model, llm_model, cross_encoder, top_k_p
 
     #documents = retrieve(query, TOP_K)
     documents = retrieve(query, top_k_param, chunk_table, embedding_model)
-    logger.info('Retrived document count:', len(documents))
+    logger.info(f'Retrived document count: {len(documents)}')
 
     if cross_encoder != "None" and len(documents) > 1:
         documents = rerank_documents(cross_encoder, documents, query, top_k_rerank=rerank_topk)
         #"cross-encoder/ms-marco-MiniLM-L-6-v2"
-        logger.info('ReRank done, document count:', len(documents))
+        logger.info(f'ReRank done, document count: {len(documents)}')
 
 
 
@@ -147,7 +147,7 @@ with gr.Blocks() as demo:
                     "mistralai/Mistral-7B-v0.1",
                     "mistralai/Mixtral-8x7B-Instruct-v0.1"
                 ],
-                value="gpt-3.5-turbo",
+                value="mistralai/Mistral-7B-Instruct-v0.2",
                 label='LLM'
             )    
     cross_encoder = gr.Radio(