Update git submodules

* Update docs/submodules/qtip from branch 'master'
  - bugfix: pip 10 can't work

    Docker image build failed on upgrading pip to 10.0.0 .
    Solution: https://github.com/pypa/pip/issues/5240#issuecomment-383115342

    Change-Id: I330dedf9dbc32d8bdac5b8cb87b5123187007e2e
    Signed-off-by: zhihui wu <wu.zhihui1@zte.com.cn>

diff --git a/docs/submodules/qtip b/docs/submodules/qtip
index 879963d..d415712 160000 (submodule)
--- a/docs/submodules/qtip
+++ b/docs/submodules/qtip
@@ -1 +1 @@
-Subproject commit 879963d90e74a4fd003bb73e8d4e50e51679f923
+Subproject commit d415712aeaf87dd6d7383a7649e15a9350aba07b