marginal/multimds: fuse_default_permissions = 1 for pjd

pjd contains lots of test cases for file permission.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Merge pull request #47 from ceph/wip-multimds-pjd

marginal/multimds: fuse_default_permissions = 1 for pjd