dirmngr: Fix initialization of assuan's nPth hook.
* dirmngr/dirmngr.c (main): Move assuan_set_system_hooks to... (thread_init): ... here.
Cherry picked master commit of:
1f8817475f59ede3f28f57edc10ba56bbdd08b49
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>