Drop unused import

src/controller/python/test/test_scripts/base.py

@@ -41,7 +41,6 @@
 from chip import ChipDeviceCtrl
 from chip.ChipStack import ChipStack
 from chip.crypto import p256keypair
-from chip.exceptions import ChipStackError
 from chip.utils import CommissioningBuildingBlocks
 from cirque_restart_remote_device import restartRemoteDevice
 from ecdsa import NIST256p