Update git submodules

* Update docs/submodules/netvirt from branch 'master'
  to 4de3bd1a5f5df210020e2e9b8b49d5798fac1c21
  - statemanager: use transaction manager

    This replaces all direct invocations of
    DataBroker::newWriteOnlyTransaction() with calls to a
    ManagedNewTransactionRunner, ensuring all such transactions are
    closed.

    Change-Id: Ib5f19025c880b6c7b534355372488d7d8ad08158
    Signed-off-by: Stephen Kitt <skitt@redhat.com>
    Signed-off-by: Sam Hague <shague@redhat.com>

diff --git a/docs/submodules/netvirt b/docs/submodules/netvirt
index a54923ba54a0866fccb5700f5264f7e4c18ea35e..4de3bd1a5f5df210020e2e9b8b49d5798fac1c21 160000 (submodule)
--- a/docs/submodules/netvirt
+++ b/docs/submodules/netvirt
@@ -1 +1 @@
-Subproject commit a54923ba54a0866fccb5700f5264f7e4c18ea35e
+Subproject commit 4de3bd1a5f5df210020e2e9b8b49d5798fac1c21