[temp.constr.normal] Rephrase comment in example (#7793)

Author: lprv

source/templates.tex

@@ -2248,7 +2248,8 @@
 struct wrapper {};
 
 template<typename... T, template<typename> concept... CTs>
-  int f(wrapper<T, CTs>...) requires (CTs<T> && ...);   // error: the fold expression expands mixed kind template parameters
+  int f(wrapper<T, CTs>...) requires (CTs<T> && ...);   // error: fold expression contains
+                                                        // different kinds of template parameters
 \end{codeblock}
 \end{example}