Fix trailing whitespace.

Author: zygoloid

source/strings.tex

@@ -1156,12 +1156,12 @@
            class Allocator = allocator<charT>>
     explicit basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
       -> basic_string<charT, traits, Allocator>;
-  
+
   template<class charT,
            class traits,
            class Allocator = allocator<charT>>
     basic_string(basic_string_view<charT, traits>,
-                 typename @\seebelow@::size_type, typename @\seebelow@::size_type, 
+                 typename @\seebelow@::size_type, typename @\seebelow@::size_type,
                  const Allocator& = Allocator())
       -> basic_string<charT, traits, Allocator>;
 }
@@ -1489,7 +1489,7 @@
          class traits,
          class Allocator = allocator<charT>>
   basic_string(basic_string_view<charT, traits>,
-               typename @\seebelow@::size_type, typename @\seebelow@::size_type, 
+               typename @\seebelow@::size_type, typename @\seebelow@::size_type,
                const Allocator& = Allocator())
     -> basic_string<charT, traits, Allocator>;
 \end{itemdecl}