[optional.dtor] Fix double negative in wording added by LWG4015.

Author: burblebee

source/utilities.tex

@@ -3661,8 +3661,7 @@
 \begin{itemdescr}
 \pnum
 \effects
-%%FIXME: Do we want "is \tcode{false}" here instead?
-If \tcode{is_trivially_destructible_v<T> != true} is \tcode{true}
+If \tcode{is_trivially_destructible_v<T>} is \tcode{false}
 and \tcode{*this} contains a value,
 calls \tcode{\exposid{val}.T::\~T()}.