SummaryState: move forwarding to fix doxy

opm/parser/eclipse/EclipseState/Schedule/SummaryState.hpp

@@ -32,6 +32,7 @@
 
 namespace Opm {
 
+class UDQSet;
 
 /*
   The purpose of this class is to serve as a small container object for
@@ -65,8 +66,6 @@ namespace Opm{
       st.has_well_var("OPY", "WGOR") => False
 */
 
-class UDQSet;
-
 class SummaryState {
 public:
     typedef std::unordered_map<std::string, double>::const_iterator const_iterator;