Update git submodules

Update git submodules

* Update docs/submodules/clover from branch 'stable/fraser'
  - Extended snort rule add to allow content field

    - Exposed the 'content' field in the GRPC server AddRules method
    - Allows the 'MALWARE-CNC User-Agent ASafaWeb Scan' signature
    in the community rules to be copied to local rules
    - Above ensures more deterministic alerts by snort each time
    the signature is hit
    - Added here to support the SDC configuration guide, which details
    how to add this scan rule via GRPC client script

    Change-Id: I6945c1e500075444134543bb9eb6003a03f1d5cc
    Signed-off-by: Eddie Arrage <eddie.arrage@huawei.com>