Clear digest header before call any get request

[renatoosousa]

In my case, I was getting bad request when calling getInstrumentIdentifierWithHttpInfo after postInstrumentIdentifierWithHttpInfo calls and I ended up finding that GET was sending the created Digest to the POST. So I had to explicitly clear it whenever I need to call the getInstrumentIdentifierWithHttpInfo.

Could you clear the field by default always before the call?