Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 394dce5eb498ae77a8a649425ac31ec830df8016
  - Remove obsolete OPNFV docker builds

    CPerf and QTIP dropped [1]

    [1] https://wiki.opnfv.org/display/PROJ/Project+Directory

    Change-Id: I8de27b7cf4bcc9cffd1336f34afcfca630d97708
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e7b433c..394dce5 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e7b433cee16a62d3390e37fed720b1a432d2b85d
+Subproject commit 394dce5eb498ae77a8a649425ac31ec830df8016