bug#3412: macros clear echo area

[Chong Yidong]

> C-x C-(
> M-! echo hi
> C-x C-)
> C-x e
>
> and you get in the echo area:
> (Type e to repeat macro)
> instead of what you used to get:
> hi

I've fixed this to omit the hint if the echo area is in use.
Thanks.