[class.expl.init] Fix incorrect note

Author: lprv

source/classes.tex

@@ -5284,7 +5284,7 @@
 If
 \tcode{T}
 is a class type with no default constructor,
-any declaration of an object of type
+any initializing declaration of an object of type
 \tcode{T}
 (or array thereof) is ill-formed if no
 \grammarterm{initializer}