Update git submodules

* Update docs/submodules/multisite from branch 'master'
  - Update the Colorado description to Danube

    There is still Colorado description in
    multisite.kingbird.installation.rst, need to update it.

    Change-Id: I9b4b0d4524d12f0a160d31d4f59c60a13f48596b
    Signed-off-by: joehuang <joehuang@huawei.com>

diff --git a/docs/submodules/multisite b/docs/submodules/multisite
index 15d60ea..22d48a7 160000 (submodule)
--- a/docs/submodules/multisite
+++ b/docs/submodules/multisite
@@ -1 +1 @@
-Subproject commit 15d60ea52b3a6dbca6da36940a87faa99e6a5f23
+Subproject commit 22d48a744158d5aafa7e2a999704eb877a77992b