Update git submodules

* Update docs/submodules/yardstick from branch 'stable/euphrates'
  - Merge "tc053 kill haproxy wrong mismatch" into stable/euphrates
  - tc053 kill haproxy wrong mismatch

    JIRA: YARDSTICK-831

    Change-Id: I587c486572f439952b8a31da664d1e2c1fb8dc27
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>
    (cherry picked from commit d70cbc5c6bd03cb68a13dcab50a12178982f5c44)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 7ba08dd..81313a8 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 7ba08ddacb134663faecec31d54c47b7ae8258a3
+Subproject commit 81313a8b4089fe31451cdc64801c689d43158ae1