[class.conv.ctor] Compactify wording in note

Author: eisenwave

source/classes.tex

@@ -2403,10 +2403,9 @@
 
 \pnum
 \begin{note}
-A non-explicit copy/move constructor\iref{class.copy.ctor} is
-a converting constructor.
-An implicitly-declared copy/move constructor is not an explicit constructor;
-it can be called for implicit type conversions.
+A non-explicit copy/move constructor\iref{class.copy.ctor},
+including one implicitly declared,
+is a converting constructor.
 \end{note}
 
 \rSec3[class.conv.fct]{Conversion functions}%