Update git submodules

* Update docs/submodules/aai/aai-common.git from branch 'master'
  to 2621450b47e79548686742d9a65ef4dc5a357d32
  - Improve security release notes

    In order to provide users with more details of project's state in
    terms of security let's divide the security release notes into three
    sections:

    - Fixed Security Issues
      Contains a list of security fixes merged during this
      release (especially those reported via OJSI tickets).

    - Known Security Issues
      Contains a list of vulnerabilities detected in project during
      release which have not been fixed yet and thus should be mitigated
      by the user.

    - Known Vulnerabilities in Used Modules
      Contains information about NexusIQ scan results

    Issue-ID: SECCOM-238
    Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
    Change-Id: I5af2a1828095720e4835e4304c2c2be397b70b7b

diff --git a/docs/submodules/aai/aai-common.git b/docs/submodules/aai/aai-common.git
index f3896fc..2621450 160000 (submodule)
--- a/docs/submodules/aai/aai-common.git
+++ b/docs/submodules/aai/aai-common.git
@@ -1 +1 @@
-Subproject commit f3896fc2e922a81e1a4947b5a0722e6322f382f7
+Subproject commit 2621450b47e79548686742d9a65ef4dc5a357d32