commit 4210720

Move the horizontal channel list on alt+left/alt+right

This was done for CTRL+P and CTRL+N but not for their ALT+arrows
counterparts.

Thanks to low-key for finding the issue.

 1@@ -554,8 +554,10 @@ func (app *App) handleKeyEvent(ev *tcell.EventKey) {
 2 	case tcell.KeyRight:
 3 		if ev.Modifiers() == tcell.ModAlt {
 4 			app.win.NextBuffer()
 5+			app.win.HorizontalBufferScrollTo()
 6 		} else if ev.Modifiers() == tcell.ModShift {
 7 			app.win.NextUnreadBuffer()
 8+			app.win.HorizontalBufferScrollTo()
 9 		} else if ev.Modifiers() == tcell.ModCtrl {
10 			app.win.InputRightWord()
11 		} else {
12@@ -564,8 +566,10 @@ func (app *App) handleKeyEvent(ev *tcell.EventKey) {
13 	case tcell.KeyLeft:
14 		if ev.Modifiers() == tcell.ModAlt {
15 			app.win.PreviousBuffer()
16+			app.win.HorizontalBufferScrollTo()
17 		} else if ev.Modifiers() == tcell.ModShift {
18 			app.win.PreviousUnreadBuffer()
19+			app.win.HorizontalBufferScrollTo()
20 		} else if ev.Modifiers() == tcell.ModCtrl {
21 			app.win.InputLeftWord()
22 		} else {