multimds: fix pjd overrides for fuse_default_permissions

Set the default (off) in the ceph task directly, so that there is only a
single overrides field that reenables.  Otherwise, the two overrides
fight each other with undefined precedence.

Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit bc1c12a460d76b11df6656043626c064aa2d8f9a)
marginal: fix pjd overrides for fuse_default_persmissions

Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit fe1d476a1f91753a90eba3eecb433948c47bf3ff)