docker: Fix bugs with mediawiki cloning
There were reports of non shallow cloning spitting out an error, and it looks like that was due to an empty string being passed as an argument.
So stop doing that, and refactor while at it!
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There were reports of non shallow cloning spitting out an error, and it looks like that was due to an empty string being passed as an argument.
So stop doing that, and refactor while at it!