Fix sample to choose between Wire and Wire1 for QTPy usage

[oculartechie]

When attempting to use bme680test.ino, it wasn't evident when using I2C interface that you might need to choose between two different buses. The changes to the sample is to show that this can be chosen in the code and does not require a change in the library.

There should be no limitations to this change. It just relies on not choosing the default specified by the library.

Tested using a QTPy ESP32 and BME688 connected via STEMMA QT

Reference: https://learn.adafruit.com/scanning-i2c-addresses

[caternuson]

@oculartechie Hey, if you're still monitoring this PR, can you please update the example to also still show the original usage:

Adafruit_BME680 bme; // I2C

Maybe just have a commented out line with a code comment:

Adafruit_BME680 bme; // I2C on default Wire bus
// Adafruit_BME680 bme(&Wire1); // I2C on specified bus, ex: Wire1

similar to how the various SPI options are also shown commented out.

Otherwise it looks like explicitly specifying the wire bus is required.

[oculartechie]

@caternuson updated as suggested

[ladyada]

remove the #define WIRE, show the default as bme(&Wire) and show the &Wire1 example as a commented out line.