[uba] Fix new false negative from #10034

[jacobtylerwalls]

def nonlocal_in_outer_frame_ok(callback, condition_a, condition_b):
    def outer():
        nonlocal callback
        def inner():
            if condition_a:
                def inner2():
                    callback()  # possibly-used-before-assignment?
                inner2()
            else:
                if condition_b:
                    def callback():
                        pass
        inner()
    outer()

we should probably raise a message here?

Originally posted by @zenlyj in #10034 (comment)