Update git submodules

* Update docs/submodules/bottlenecks from branch 'stable/danube'
  - Delete testcase of rubbos and vstf.

    JIRA:BOTTLENECK-167

    This patch will delete vstf and rubbos testcase code.
    Include some testcase config file,
    if there will be someone who want to use this testcase
    maybe B or C version code will contain those testcase.
    if you use the D version code to run this two testcase
    we will info you that:
        Rubbos testsuite is not updating anymore.
        This entrance for running Rubbos within Bottlenecks is no longer supported.

    Change-Id: I04e4042ff3998b3696df2ed47a9ffab6f1620ec3
    Signed-off-by: liyin <liyin11@huawei.com>
    (cherry picked from commit 6a8257127b3dce1f18a650afe6921a34b6c6f5b8)

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index 6dff90f..fb9e1a7 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit 6dff90faee27dc5569255f5cb6ba72ae5e22b924
+Subproject commit fb9e1a726d3a598494fd38330848ef676219a47a