small fix.

src/libgmshdg/param_loader.cpp

@@ -134,7 +134,7 @@ parameter_loader_base::load_file(const std::string& fn)
 int
 parameter_loader_base::sim_approxorder(void) const
 {
-    auto ao = lua["sim"]["approx_order"];
+    int ao = lua["sim"]["approx_order"];
     if (ao < 1)
         ao = 1;
     return ao;
@@ -143,7 +143,7 @@ parameter_loader_base::sim_approxorder(void) const
 int
 parameter_loader_base::sim_geomorder(void) const
 {
-    auto go = lua["sim"]["geom_order"];
+    int go = lua["sim"]["geom_order"];
     if (go < 1)
         go = 1;
     return go;