Update git submodules

* Update docs/submodules/compass4nfv from branch 'stable/fraser'
  - Fix downloading lxc image

    Change-Id: I195a2203c9c998e264c54effc37346fec67c6c6a
    Signed-off-by: Harry Huang <huangxiangyu5@huawei.com>

diff --git a/docs/submodules/compass4nfv b/docs/submodules/compass4nfv
index f99a7eb..62a998e 160000 (submodule)
--- a/docs/submodules/compass4nfv
+++ b/docs/submodules/compass4nfv
@@ -1 +1 @@
-Subproject commit f99a7eb3d25bb893c144135d3af3109402aac8bd
+Subproject commit 62a998e04b480df09ad479c63ad836cbc82af5b6