feat(net): support proxy configuration via config file (#1359)

* support proxy

* debug

* debug2

* del debug

* add proxy configuration with env var fallback

* comments to en

* refactor(env): fallback env

---------

Co-authored-by: jyxjjj <773933146@qq.com>

internal/conf/config.go

@@ -131,6 +131,7 @@ type Config struct {
 	FTP                   FTP         `json:"ftp" envPrefix:"FTP_"`
 	SFTP                  SFTP        `json:"sftp" envPrefix:"SFTP_"`
 	LastLaunchedVersion   string      `json:"last_launched_version"`
+	ProxyAddress          string      `json:"proxy_address" env:"PROXY_ADDRESS"`
 }
 
 func DefaultConfig(dataDir string) *Config {
@@ -244,5 +245,6 @@ func DefaultConfig(dataDir string) *Config {
 			Listen: ":5222",
 		},
 		LastLaunchedVersion: "",
+		ProxyAddress:        "",
 	}
 }