encoding/htmlindex: use PreferSameScript
encoding/htmlindex: use PreferSameScript

has no effect now, but captures intent better
so should be better for future compatibility.

Change-Id: Ia39bb0492feebf1ba2be52badde2fb31f3f0ed7b
Reviewed-on: https://go-review.googlesource.com/54690
Run-TryBot: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Nigel Tao <58ae08b3356928ff9c67562b4719487d54fe8348@golang.org>

golang/text