Update git submodules

* Update docs/submodules/doctor from branch 'master'
  - Specify the filename for 'w' filemode

    FileHandler use 'a' mode in default for writing the file.

    Change-Id: Ie19d80e5ff286da2722634787dcffe36234c0119
    Signed-off-by: dongwenjuan <dong.wenjuan@zte.com.cn>

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index c9fb520..9666593 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit c9fb5207df1a3aa579d86f413587ec47c41063af
+Subproject commit 96665938926b5083cf917517e2ecb7c7267d72c1