[LORA] Fix buffer overflow when converting binary packets to hex (#2402)

TheengsUtils::_rawToHex() formats each byte with "%02X\r", so the last
sprintf writes two bytes past the 2 * size hex digits (the '\r' and the
terminating null). LORAtoX() sized its buffer 2 * packetSize + 1, one
byte short, overflowing the stack for every binary LoRa packet.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

main/gatewayLORA.cpp

@@ -459,7 +459,7 @@ void LORAtoX() {
         return;
       }
       // We have non-ascii data: create hex string of the data
-      char hex[packetSize * 2 + 1];
+      char hex[packetSize * 2 + 2]; // _rawToHex writes "%02X\r" per byte: needs 2 * size + 2
       TheengsUtils::_rawToHex(packet, hex, packetSize);
       // Terminate with a null character
       hex[packetSize * 2] = 0;