Update git submodules

Update git submodules

* Update docs/submodules/clover from branch 'master'
  - Merge "Add file upload/download and configure URL paths"
  - Add file upload/download and configure URL paths

    - Compile nginx from source in order to employ additional modules
    - Add nginx-upload-module for high performance file upload that
    avoids the need for file copies with a web application.
    - File upload allows for placement of files for file download
    for performance benchmarking.
    - File upload can also be used directly for bi-directional throughput
    testing having emulated clients upload files while file downloads
    simultaneously occur.
    - Nginx file upload stores files with hash to avoid conflicting
    file names. Upload block in nginx config is configured to send
    REST message to clover-controller with file metadata (original
    filename, size, etc.) clover-controller will be responsible for
    modifying the hashed filename and placing in a target directory
    within an nginx server.
    - Build also adds nginx-rtmp module to act as streaming media server
    L7 loader will be extended to fetch streaming files from RTMP
    servers.

    - Add ability to create directories in server site root
    and create the location directive(s) in nginx configuration
    - Separated upload for configuration (download
    files in various paths) from upload for testing (upload
    to create bi-directional session throughput)
    - Upload for testing does not sent upload metadata to
    clover-controller
    - Added ability to move upload files to file folders in the nginx site
    root to use for download
    - Delete files in upload folder
    - Fixed issue with 426 Upgrade Required error message
    when upload module sends upload metadata to clover-controller
    - Added server name to metadata sent to clover-controller

    Change-Id: Ib4cf6240f92360b82f378c062675f4fdaa19ca93
    Signed-off-by: Eddie Arrage <eddie.arrage@huawei.com>