bug#25845: 25.1; underline height moves

[Eli Zaretskii]

> From: ynyaaa@gmail.com
> Date: Thu, 23 Feb 2017 11:59:44 +0900
> 
> Evaluating the form below, underline is displayed as one line at first.
> Then move text cursor on Y, underline of Y moves down.
> Then move text cursor on X and insert any text,
> height of underline of Y moves back.
> 
> (insert (propertize "X" 'face '(:underline t))
>         (propertize "Y" 'face '(:underline t :height 5.0)))

Thanks, fixed.

Could someone please make sure the NS build still compiles after my
changes in nsterm.m to fix this bug?