LU-9960 osd-zfs: don't auto-upgrade quota

LU-9960 osd-zfs: don't auto-upgrade quota

To preserve the ability to down-grade from 0.7.x to 0.6.x,
don't auto-upgrade quotas.
Print warning if quotas haven't been upgraded when mouting with 0.7.0.
Do check based on zpool feature in sanity-quota instead of just
version.

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: I2b0dcba3a230c9b2dec3d07d1b4ca6f1a1717d47
Reviewed-on: https://review.whamcloud.com/28924
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>