Resolve "read-only dynamic attribute with dummy write function fails in 9.3.5"
requested to merge 470-read-only-dynamic-attribute-with-dummy-write-function-fails-in-9-3-5 into develop
Closes #470 (closed)
The reason is that __DeviceImpl__add_attribute
method still tries to wrap this dummy method, which is supposed to be never called
So the solution is - wrap r_meth only if attrbute readable and w_meth if it is writable