make the typing import excepted

Author: Neradoc

adafruit_usb_host_mass_storage.py

@@ -14,11 +14,15 @@
 
 import struct
 import time
-from typing import Optional
 import usb.core
 from micropython import const
 import adafruit_usb_host_descriptors
 
+try:
+    from typing import Optional
+except ImportError:
+    pass
+
 __version__ = "0.0.0+auto.0"
 __repo__ = (
     "https://github.com/adafruit/Adafruit_CircuitPython_USB_Host_Mass_Storage.git"