RTU cleanup and fixes

rtu/backplane.lua

@@ -150,7 +150,7 @@ function backplane.detach(type, device, iface, print_no_fp)
 
                     databus.tx_hw_wl_modem(true)
                 elseif wd_nic and wd_nic.is_connected() then
-                    _bp.act_nic = _bp.wd_nic
+                    _bp.act_nic = wd_nic
 
                     comms.switch_nic(_bp.act_nic)
                     log.info("BKPLN: switched comms to wired modem")

rtu/rtu.lua

@@ -326,7 +326,6 @@ function rtu.comms(version, nic, conn_watchdog)
         m_pkt.make(msg_type, msg)
         s_pkt.make(self.sv_addr, self.seq_num, PROTOCOL.SCADA_MGMT, m_pkt.raw_sendable())
 
----@diagnostic disable-next-line: need-check-nil
         nic.transmit(config.SVR_Channel, config.RTU_Channel, s_pkt)
         self.seq_num = self.seq_num + 1
     end

rtu/startup.lua

@@ -121,7 +121,6 @@ local function main()
     log.debug("boot> running uinit()")
 
     if uinit(config, __shared_memory) then
-
         -- start UI
         local message
         rtu_state.fp_ok, message = renderer.try_start_ui(config, units)