LU-16790 man: fix lctl-nodemap-modify man page

LU-16790 man: fix lctl-nodemap-modify man page

The section about the rbac property is malformed, regarding line feeds
in particular.
The forbid_encryption property is not mentioned.
Default values for admin, trusted, deny_unknown, audit_mode and
readonly_mount properties are not expressed correctly. These
properties grok 0 or 1.

Lustre-change: https://review.whamcloud.com/50918
Lustre-commit: 7e252d4c6c7049b16e28359c776d748d74c0ff3c

Fixes: 84e7220830 ("LU-16524 sec: add fscrypt_admin rbac role")
Test-Parameters: trivial
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I712e4d21b3038d87c50bb12206cbcc92ef4b615f
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Patrick Farrell <pfarrell@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51831
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Andreas Dilger <adilger@whamcloud.com>