Fix for Issue #770 - Provide a better error message when timers are still available.
Fix for Issue #770 - Provide a better error message when timers are still available.

adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython