test/pybind/rbd: skip test_deep_copy_clone if layering not enabled

[trociny]

(otherwise it will fail on protect snap)

Signed-off-by: Mykola Golub mgolub@suse.com

[trociny]

======================================================================
ERROR: test_rbd.TestImage.test_deep_copy_clone
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/mgolub/ceph/ceph.trociny/src/test/pybind/test_rbd.py", line 527, in test_deep_copy_clo
ne
    self.image.protect_snap('snap1')
  File "rbd.pyx", line 2440, in rbd.Image.protect_snap (/home/mgolub/ceph/ceph.trociny/build/src/pyb
ind/rbd/rbd.c:24766)
FunctionNotSupported: [errno 38] error protecting snapshot image45@snap1

[dillaman]

lgtm