Update git submodules

* Update docs/submodules/doctor from branch 'master'
  - refactor failure inject

    JIRA: DOCTOR-116

    Change-Id: I14deda4ccb47414cff139a522a9196b68e92500e
    Signed-off-by: dongwenjuan <dong.wenjuan@zte.com.cn>

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index 836a893..19f7ba7 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit 836a8932d6c6a502980009b9578f0c6ecf64cb47
+Subproject commit 19f7ba75850c52e1ae163766b64b6d153e8d7e1b