Update m_nSize when shrinking wxArrayString (fixes #10591).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59533 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/arrstr.cpp

@@ -206,6 +206,7 @@ void wxArrayString::Shrink()
         pNew[j] = m_pItems[j];
     delete [] m_pItems;
     m_pItems = pNew;
+    m_nSize = m_nCount
   }
 }