Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "MaaS: Disable network discovery"
  - MaaS: Disable network discovery

    In case nodes are already powered on and have an IP in the same
    range as the new MaaS DHCP one (e.g. from a previous deploy),
    MaaS API will reject the subnet creation due to overlapping
    addresses. Try to work around this by disabling network discovery.

    Change-Id: I70a33c552bf38a7ccbc1bb7e90c21f424f082bc5
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index ab74fd4..30b1f3b 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit ab74fd4075c0e847acebb61b481236b00132702d
+Subproject commit 30b1f3bdaa5de7e52d41a13d231d2bca3838e449