Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 45b0c222c081d4614dbd6aba2024336e8d4d3351
  - Leverage opnfv-build instead of lf-virtual1

    Change-Id: If8ba71bf4015b2e8e246d8f3e299680f33b6a2cb
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 5b4b987..45b0c22 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 5b4b987d68d6ad0e35bbb247d386ba66c37e66dc
+Subproject commit 45b0c222c081d4614dbd6aba2024336e8d4d3351