Fixed fd leak, and indented

[jakobdalsgaard]

Basically moved this part:

const sensor = await ina219(Number(options.i2c_address), options.i2c_bus);
await sensor.calibrate32V2A();

outside the readina219 function to prevent filedescriptor leak -- also redid the catch statement.

Fixing this leak is essential for running SignalK for many weeks.