add useIPv4 option to two stage rsync (#150)

worker/provider.go

@@ -176,6 +176,7 @@ func newMirrorProvider(mirror mirrorConfig, cfg *Config) mirrorProvider {
 			logDir:            logDir,
 			logFile:           filepath.Join(logDir, "latest.log"),
 			useIPv6:           mirror.UseIPv6,
+			useIPv4:           mirror.UseIPv4,
 			interval:          time.Duration(mirror.Interval) * time.Minute,
 			retry:             mirror.Retry,
 			timeout:           time.Duration(mirror.Timeout) * time.Second,