parse/value: remove pessimising move

parse/value.hpp

@@ -33,7 +33,7 @@ namespace cruft::parse {
         T res = value<T> (data);
         if (!data.empty ())
             throw std::invalid_argument ("unable to parse");
-        return std::move (res);
+        return res;
     }
 
     template <typename T> T from_string (const char *data) { return from_string<T> (cruft::view (data)); }