Use LORA_DIO1 as RadioLib GPIO for SX127x chips (#2290)

* When channel is active, first try receiving that packet
Afterwards we'll try transmitting again

* Remove setStandby in startSend
Already done in isChannelActive()

* Set LORA_DIO1 as RadioLib GPIO for SX127x

* LORA_DIO1 for Heltec v1, overlaps with GPS_TX
Set to RADIOLIB_NC for now

* If receive was not successful, startReceive doesn't trigger the interrupt
So we have to go back to transmitting anyway

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/mesh/RadioLibInterface.cpp

@@ -218,8 +218,9 @@ void RadioLibInterface::onNotify(uint32_t notification)
                 setTransmitDelay(); // currently Rx/Tx-ing: reset random delay
             } else {
                 if (isChannelActive()) { // check if there is currently a LoRa packet on the channel
-                    // LOG_DEBUG("Channel is active: set random delay\n");
-                    setTransmitDelay(); // reset random delay
+                    // LOG_DEBUG("Channel is active, try receiving first.\n");
+                    startReceive(); // try receiving this packet, afterwards we'll be trying to transmit again
+                    setTransmitDelay();
                 } else {
                     // Send any outgoing packets we have ready
                     meshtastic_MeshPacket *txp = txQueue.dequeue();
@@ -388,8 +389,6 @@ void RadioLibInterface::startSend(meshtastic_MeshPacket *txp)
         LOG_WARN("startSend is dropping tx packet because we are disabled\n");
         packetPool.release(txp);
     } else {
-        setStandby(); // Cancel any already in process receives
-
         configHardwareForSend(); // must be after setStandby
 
         size_t numbytes = beginSending(txp);