mgr/PyModule: put mgr_module_path before Py_GetPath()

mgr/PyModule: put mgr_module_path before Py_GetPath()

pip comes with _vendor/progress. so there is chance to import the vendored
version of "progress" module instead of the "progress" mgr module, and
fail to import the latter.

in this change, the order of paths are rearranged so the configured
`mgr_module_path` is put before the return value of `Py_GetPath()`.

Fixes: https://tracker.ceph.com/issues/50058
Signed-off-by: Kefu Chai <kchai@redhat.com>