Update git submodules

* Update docs/submodules/parser from branch 'master'
  - Fix heat_stack_owner bug

    In env installed by apex, there is no role of heat_stack_owner, so it
    need to separate the condition  in script.

    JIRA:PARSER-157

    Change-Id: Ie40715268a1124b57f0bf36ddc566bbcdbed964b
    Signed-off-by: shangxdy <shang.xiaodong@zte.com.cn>

diff --git a/docs/submodules/parser b/docs/submodules/parser
index a224201..51a4cb9 160000 (submodule)
--- a/docs/submodules/parser
+++ b/docs/submodules/parser
@@ -1 +1 @@
-Subproject commit a224201e408aca8424b076b5e46138b5e322a9ef
+Subproject commit 51a4cb9a4026037147da64b2353ec44002c7a7a7