Remove one extraneous registration of ThreadsPerProcess parameter

opm/simulators/flow/FlowMain.hpp

@@ -101,12 +101,11 @@ namespace Opm {
                 ("Developer option to see whether logging was on non-root processors. "
                  "In that case it will be appended to the *.DBG or *.PRT files");
 
-            ThreadManager::registerParameters();
-            Simulator::registerParameters();
-
             // register the base parameters
             registerAllParameters_<TypeTag>(/*finalizeRegistration=*/false);
 
+            Simulator::registerParameters();
+
             detail::hideUnusedParameters<Scalar>();
 
             Parameters::endRegistration();