get_readable_message: Acquire lock before accessing the download_dict

Signed-off-by: lzzy12 <jhashivam2020@gmail.com>

README.md

@@ -35,7 +35,7 @@ For Debian based distros
 ```
 sudo apt install aria2c
 ```
-For Arch and it's derivatives:
+- For Arch and it's derivatives:
 ```
 sudo pacman -S aria2
 ```

bot/helper/ext_utils/bot_utils.py

@@ -77,7 +77,10 @@ def get_download_str():
         return result
 
 
-def get_readable_message(progress_list: list = download_dict.values()):
+def get_readable_message(progress_list: list = None):
+    if progress_list is None:
+        with download_dict_lock:
+            progress_list = list(download_dict.values())
     msg = ''
     for status in progress_list:
         msg += f'<b>Name:</b> {status.name()}\n' \