RFR: skara: explicitly update submodules

[Robin Westberg]

On Mon, 30 Mar 2020 12:09:02 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review this patch that makes the `git skara update` explicitly update
> eventual submodules for better compatibility with older git clients.
> 
> Thanks,
> Erik

Looks good!

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Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/550