feat: add proxy config in telegram dialer

config.example.toml

@@ -1,4 +1,4 @@
-workers = 4          # 同时下载文件数
+workers = 4 # 同时下载文件数
 
 [telegram]
 token = ""                                    # Bot Token
@@ -6,6 +6,10 @@ admins = [777000]                             # 你的 user_id
 app_id = 123456                               # Telegram API ID
 app_hash = "0123456789abcdef0123456789abcdef" # Telegram API Hash
 
+[telegram.proxy]
+enable = false
+url = "socks5://127.0.0.1:7890" # 代理地址
+
 [log]
 level = "DEBUG" # 日志等级