set discovered_python_interpreter if ansible_python_interpreter is defined
set discovered_python_interpreter if ansible_python_interpreter is defined

If the user has set the `ansible_python_interpreter`, ansible will not try to
discover python, so `discovered_python_interpreter` will not be set.

Solution: Set `discovered_python_interpreter` to `ansible_python_interpreter`
if `ansible_python_interpreter` is defined

Signed-off-by: Johannes Kastl <e60828858c74623402ca6ee33d59397621895367@b1-systems.de>

ceph/ceph-ansible,ceph/ceph-ansible