chore: refactor logx file time format (#4335)

core/logx/logs_test.go

@@ -856,6 +856,7 @@ func testSetLevelTwiceWithMode(t *testing.T, mode string, w *mockWriter) {
 		Encoding:       plainEncoding,
 		Stat:           false,
 		TimeFormat:     time.RFC3339,
+		FileTimeFormat: time.DateTime,
 	})
 	SetUp(LogConf{
 		Mode:  mode,

core/logx/rotatelogger.go

@@ -30,6 +30,7 @@ const (
 var (
 	// ErrLogFileClosed is an error that indicates the log file is already closed.
 	ErrLogFileClosed = errors.New("error: log file closed")
+
 	fileTimeFormat = time.RFC3339
 )