[SX127x] Added missing standby command

src/modules/SX127x.cpp

@@ -467,6 +467,9 @@ int16_t SX127x::readData(uint8_t* data, size_t len) {
   int16_t modem = getActiveModem();
   size_t length = len;
 
+  // put module to standby
+  standby();
+
   if(modem == SX127X_LORA) {
     // len set to maximum indicates unknown packet length, read the number of actually received bytes
     if(len == SX127X_MAX_PACKET_LENGTH) {