ceph_osd_bootstrap_key fact: increase timeout

Like we do in ceph_keyring fact with 10 seconds, let's increase the
timeout to avoid this situation when compiling the catalog:

ceph command timeout in ceph_osd_bootstrap_key fact
Traceback (most recent call last):
  File "/usr/bin/ceph", line 830, in <module>
    sys.exit(main())
  File "/usr/bin/ceph", line 819, in main
    sys.stdout.flush()
IOError: [Errno 32] Broken pipe

10 seconds is the same value as in ceph_keyring fact.