fix disable and enable llm setting in dialog (#616)

### What problem does this PR solve?
#614 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/apps/dialog_app.py

@@ -35,13 +35,7 @@ def set_dialog():
     top_n = req.get("top_n", 6)
     similarity_threshold = req.get("similarity_threshold", 0.1)
     vector_similarity_weight = req.get("vector_similarity_weight", 0.3)
-    llm_setting = req.get("llm_setting", {
-        "temperature": 0.1,
-        "top_p": 0.3,
-        "frequency_penalty": 0.7,
-        "presence_penalty": 0.4,
-        "max_tokens": 215
-    })
+    llm_setting = req.get("llm_setting", {})
     default_prompt = {
         "system": """你是一个智能助手，请总结知识库的内容来回答问题，请列举知识库中的数据详细回答。当所有知识库内容都与问题无关时，你的回答必须包括“知识库中未找到您要的答案！”这句话。回答需要考虑聊天历史。
 以下是知识库：

api/utils/file_utils.py

@@ -67,7 +67,7 @@ def get_rag_python_directory(*args):
 
 
 def get_home_cache_dir():
-    dir = os.path.join(os.path.expanduser('~'), ".raglow")
+    dir = os.path.join(os.path.expanduser('~'), ".ragflow")
     try:
         os.mkdir(dir)
     except OSError as error: