[test][1pnc] Fix deprecation warninng for nonequil tests

test/porousmediumflow/1pnc/implicit/nonequilibrium/main.cc

@@ -101,7 +101,7 @@ int main(int argc, char** argv) try
     // the grid variables
     using GridVariables = GetPropType<TypeTag, Properties::GridVariables>;
     auto gridVariables = std::make_shared<GridVariables>(problem, fvGridGeometry);
-    gridVariables->init(x, xOld);
+    gridVariables->init(x);
     problem->setGridVariables(gridVariables);
 
     // get some time loop parameters