don't check for chrome binary binary when impersonate is disabled

src/config/config.go

@@ -95,9 +95,11 @@ func SetConfig(configFile string) (*Config, error) {
 		return nil, proxyPoolThirdpartyErr
 	}
 
+	if config.ProxyCheckImpersonateChrome {
 		if _, err := os.Stat(config.ProxyCheckImpersonateChromeBinary); os.IsNotExist(err) {
 			return nil, errors.New(fmt.Sprintf(`curl-impersonate-chrome binary does not exist: "%s"`, config.ProxyCheckImpersonateChromeBinary))
 		}
+	}
 	cmd := exec.Command(config.ProxyCheckImpersonateChromeBinary, "--help")
 	err = cmd.Run()
 	if err != nil {