Update git submodules

* Update docs/submodules/netconf from branch 'master'
  to 72bcb09b111b10f7db3af61b9e4a628291eec209
  - Add missing synchronisation

    AbstractNetconfSessionNegotiator synchronises access to state in
    changeState(); this also needs to be done in ifNegotiatedAlready.
    (FindBugs now flags this and fails the build.)

    Change-Id: Id2209e1987429f3b754a2c7afc1a7e47dc4135ab
    Signed-off-by: Stephen Kitt <skitt@redhat.com>

diff --git a/docs/submodules/netconf b/docs/submodules/netconf
index 4e39e49ef541d25099afc4c2ff80d89b04b24103..72bcb09b111b10f7db3af61b9e4a628291eec209 160000 (submodule)
--- a/docs/submodules/netconf
+++ b/docs/submodules/netconf
@@ -1 +1 @@
-Subproject commit 4e39e49ef541d25099afc4c2ff80d89b04b24103
+Subproject commit 72bcb09b111b10f7db3af61b9e4a628291eec209