Update ds3.py
Update ds3.py

Fixing a spelling mistake.
chanchett/ds3_python_sdk,chanchett/ds3_python_sdk_,SpectraLogic/ds3_python_sdk,chanchett/ds3_python_sdk,chanchett/ds3_python_sdk,SpectraLogic/ds3_python_sdk,SpectraLogic/ds3_python_sdk