srsue,phy: initialize NR PHY only if NR carriers are defined in ue.conf

srsue/src/ue.cc

@@ -133,10 +133,12 @@ int ue::init(const all_args_t& args_)
       srsran::console("Error initializing PHY.\n");
       ret = SRSRAN_ERROR;
     }
+    if (args.phy.nof_nr_carriers > 0) {
       if (lte_phy->init(phy_args_nr, lte_stack.get(), lte_radio.get())) {
         srsran::console("Error initializing NR PHY.\n");
         ret = SRSRAN_ERROR;
       }
+    }
     if (lte_stack->init(args.stack, lte_phy.get(), lte_phy.get(), gw_ptr.get())) {
       srsran::console("Error initializing stack.\n");
       ret = SRSRAN_ERROR;