Relocate during replace

Fixes #1587

internal/display/bufwindow.go

@@ -139,6 +139,9 @@ func (w *BufWindow) Relocate() bool {
 	ret := false
 	activeC := w.Buf.GetActiveCursor()
 	cy := activeC.Y
+	if activeC.HasSelection() {
+		cy = activeC.CurSelection[0].Y
+	}
 	scrollmargin := int(b.Settings["scrollmargin"].(float64))
 	if cy < w.StartLine+scrollmargin && cy > scrollmargin-1 {
 		w.StartLine = cy - scrollmargin