[meta.reflection.array] Use usual "<boolean> is true" phrasing

Author: tkoeppe

source/meta.tex

@@ -5564,8 +5564,7 @@
 Let $P$ be
 \begin{itemize}
 \item
-  If \tcode{sizeof...($V$) > 0},
-  %FIXME: is true
+  If \tcode{sizeof...($V$) > 0} is true,
   then the template parameter object\iref{temp.param}
   of type \tcode{const T[\brk{}sizeof...(\brk{}$V$)]}
   initialized with \tcode{\{[:$V$:]...\}}.