Update git submodules

* Update docs/submodules/doctor from branch 'stable/danube'
  - Fix release notes reference

    Change-Id: I4351600917570e3b9eddeefab43fee7882d20ddf
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>
    (cherry picked from commit bcffa7ef747c75a18d3b38182737222a6010ce36)

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index b2b4b7d..5f48662 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit b2b4b7df99c84e07c9e62fd0da286c562ffb7051
+Subproject commit 5f4866298d0ff7c99d954261b06ff65a9782ca2b