runtime: Improve error message when setting read-only property

Formerly, if you wrote
   SPI.frequency = 0
you would get the sightly erroneous error message
   AttributeError: 'SPI' object has no attribute 'frequency'
In this case, a better message would read
   AttributeError: 'SPI' object cannot assign attribute 'frequency'

This new message will both be used in the case where the attribute doesn't
exist at all (and the object has no dynamic attributes; most instances of
built in types behave this way), or if the attribute exists but is
read-only.

0 files changed, 0 insertions, 0 deletions