Refactor 1dbe94c8ac restored the 'old' proper way to directly call the
python type (i.e. use the python's implementation to create objects),
instead of using the 'specialized' type creation code.
However, the handling of the ugly `rna_disallow_writes` global was only
added later to the 'workaround' part of the code, but not to the original
'canonical' one.
This commit copies the handling of `rna_disallow_writes` back into the
now active part of the code.
This solves the `is_readonly_init` unused variable build warning.
NOTE: At some point the BPY code needs a good cleanup pass, there are
way to many pieces of codes #ifdef'ed there.
Blender is the free and open source 3D creation suite.
It supports the entirety of the 3D pipeline-modeling, rigging, animation, simulation, rendering, compositing,
motion tracking and video editing.