Fixed compile warning in network port object.

src/bacnet/basic/object/netport.c

@@ -2824,6 +2824,7 @@ bool Network_Port_IPv6_Gateway_Zone_Index_Set(
     return status;
 }
 
+#if (BBMD_CLIENT_ENABLED) && defined(BACAPP_HOST_N_PORT)
 /**
  * @brief Write the FD BBMD Address
  * @param object_instance [in] BACnet network port object instance number
@@ -2903,6 +2904,7 @@ static bool Network_Port_FD_BBMD_Address_Write(
 
     return status;
 }
+#endif
 
 /**
  * For a given object instance-number, gets the MS/TP Max_Info_Frames value