deepupdate change recursion to loop

[lucasfcnunes]

Solves RecursionErrors exceptions/crashes caused by bloated memory use or high recursion depth when calling deepupdate().
*The same issues can occur on copy.deepcopy() calls.

[lafrech]

Do you have a real life use case where the update process significantly eats up the memory to a point where the app crashes?

Or is this more of a theoretical issue?

[lucasfcnunes]

oh, i did.
at the time of this commit i was actually facing this issue

i was recursively building an api spec using a web scraping engine
i tried running it on a new async thread to tweak the python stack parameters, but i ended up having real seg faults/core dumps