ID 434549 - Using mari.prefs.get() on Misc./Shelf/updateIconsAction doesn't return a mari.action

Problem summary
Using mari.prefs.get() on Misc./Shelf/updateIconsAction doesn't return a mari.action

Customer reported version
mari.4.6v3

Customer reported platform
windows10

Steps to reproduce

1) Open Mari, and in the Python Console run:

mari.prefs.get("Misc./Shelf/updateIconsAction")

Expected behaviour
For it to return the mari.action for that preference item

Actual behaviour
It errors saying:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
RuntimeError: Can't find converter for 'MriAction*'.

Reproduced by support
This bug has been reproduced in:

Mari 4.6v3 - Windows 10

Mari 4.5v1 - Windows 10

Mari 4.0v1 - Windows 10

Mari 3.0v1 - Windows 10 *Returns None rather than the error or the object - regression

Unable to reproduce bug in:
Mari 2.6v5 - Windows 10 *Returns the mriAction object as it still exists in this Mari version

Earliest version tested
Mari 2.6v5 - This issue doesn't appear in this version and has regressed