Update git submodules

* Update docs/submodules/msb/apigateway.git from branch 'master'
  to 56e9b834e44dc7a506ce94e8a222272b0270bbf0
  - Automation adds msb-apigateway-offeredapis.rst
    
    Issue-ID: CIMAN-376
    
    Change-Id: I8f01294f925e585cc9cdf1f661f873cfa966b09f
    Signed-off-by: lf-jobbuilder <releng+lf-jobbuilder@linuxfoundation.org>
    
diff --git a/docs/submodules/msb/apigateway.git b/docs/submodules/msb/apigateway.git
index 7153154..56e9b83 160000
--- a/docs/submodules/msb/apigateway.git
+++ b/docs/submodules/msb/apigateway.git
@@ -1 +1 @@
-Subproject commit 71531542ea1f5def5b946c6b0a5b0a176718ffb4
+Subproject commit 56e9b834e44dc7a506ce94e8a222272b0270bbf0