Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 10076a94d789772e73f2d6da6da1729c05dc3950
  - Revert "Use label opnfv-build instead of harcoded lf-build6"

    This reverts commit 2a2791a2eab1f870413a1617f356adc70a16de3f.

    Change-Id: I3ad716423a8da4cea44d028be0e69681cf9a2507
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fe01e2d..10076a9 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fe01e2d8ea9d3578cbeed5fd2b7ec50950c04b0a
+Subproject commit 10076a94d789772e73f2d6da6da1729c05dc3950