[BUG] AttributePropery with mutable, non-auto-create default loses its value on restart

[chiizujin]

This seems to be a recurrence of #3488 (resolved by b8e37f9)

I can't recall how much I tested this after the above fix but I am still seeing this happening. Here is a more basic example:

Using this object:

class TestObject(Object):
    test_list = AttributeProperty(list, autocreate=False)
    test_dict = AttributeProperty(dict, autocreate=False)

>py self.search("test").test_list
[]

>py self.search("test").test_list.append(1)

>py self.search("test").test_list
[1]

>restart
(...)

>py self.search("test").test_list
[]

If an empty list is assigned to the proprty first, it works as expected:

>py self.search("test").test_list = []
>py self.search("test").test_list.append(1)
>py self.search("test").test_list
[1]

>restart
(...)

>py self.search("test").test_list
[1]

Similarly for a dictionary:

>self.search("test").test_dict
{}

>py self.search("test").test_dict[1] = 1

>py self.search("test").test_dict
{1: 1}

>restart
(...)

>py self.search("test").test_dict
{}

Again, it works as expected if assigning first:

>py self.search("test").test_dict = {}
>py self.search("test").test_dict[1] = 1
>py self.search("test").test_dict
{1: 1}

>restart
(...)

>py self.search("test").test_dict
{1: 1}

I have not tested sets but I suspect they may have the same issue.

This does not occur with autocreate=True.