bindings: python: fix a memory leak in error path
bindings: python: fix a memory leak in error path

We need to decref the iter object in Line.set_values() if the
conversion from python to C unsigned integer fails.

Signed-off-by: Bartosz Golaszewski <108de5fbc428215dc26df4468b48691526611148@gmail.com>

brgl/libgpiod,brgl/libgpiod,brgl/libgpiod,brgl/libgpiod