Update git submodules

* Update docs/submodules/compass4nfv from branch 'stable/euphrates'
  - fix ceph reboot issue

    When storage nodes reboot or shutdown,
    the partitions of loop device will lose.
    We add the command partprobe -s {{loopdevice}} to rc.local,
    it will reload the partitions, when boot up the storage nodes.

    Change-Id: I31dfca953aa254fa516421a494318b01cd39675c
    Signed-off-by: wutianwei <wutianwei1@huawei.com>

diff --git a/docs/submodules/compass4nfv b/docs/submodules/compass4nfv
index 466732f..e4a8e01 160000 (submodule)
--- a/docs/submodules/compass4nfv
+++ b/docs/submodules/compass4nfv
@@ -1 +1 @@
-Subproject commit 466732f9477b9ad208761651290c6c046ba5f690
+Subproject commit e4a8e01da5834049f210186610a291e9c5f6747d