[container.adaptors.general] Remove using typename from expos-only alias template

Author: AlisdairM

source/containers.tex

@@ -15581,8 +15581,7 @@
 may appear in deduction guides for container adaptors:
 \begin{codeblock}
 template<class Allocator, class T>
-  using @\exposid{alloc-rebind}@ =                      // \expos
-    typename allocator_traits<Allocator>::template rebind_alloc<T>;
+  using @\exposid{alloc-rebind}@ = allocator_traits<Allocator>::template rebind_alloc<T>;   // \expos
 \end{codeblock}
 
 \rSec2[queue.syn]{Header \tcode{<queue>} synopsis}