Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Fix Doctor run on 'doctor-{installer}-verify' slave

    Change-Id: I65a2a3c6643cba870eec2f794199bb824c6b868c
    Signed-off-by: Delia Popescu <delia.popescu@enea.com>
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 6f56cde..75cc81a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 6f56cde8284f3b20e2b02e0322f2c89c1b770f23
+Subproject commit 75cc81aff474220fb437474885a650d0c736d41b