Fixed REG_LR_SYNCH_TIMEOUT register write to only happen when symbNum is different from 0

Author: mluis1

src/radio/sx126x/sx126x.c

@@ -370,8 +370,11 @@ void SX126xSetLoRaSymbNumTimeout( uint8_t symbNum )
     reg = mant << ( 2 * exp + 1 );
     SX126xWriteCommand( RADIO_SET_LORASYMBTIMEOUT, &reg, 1 );
 
-    reg = exp + ( mant << 3 );
-    SX126xWriteRegister( REG_LR_SYNCH_TIMEOUT, reg );
+    if( symbNum != 0 )
+    {
+        reg = exp + ( mant << 3 );
+        SX126xWriteRegister( REG_LR_SYNCH_TIMEOUT, reg );
+    }
 }
 
 void SX126xSetRegulatorMode( RadioRegulatorMode_t mode )