Re: [PATCH] ci: make the whitespace checker more robust

"Johannes Schindelin via GitGitGadget" [off-list ref]
writes:

    One thing we discussed earlier whether the log should be pasted as
    pre-formatted text or not, and we fell on the side of not pre-formatting
    it. However, in my tests, this does not look right
    [https://github.com/dscho/git/pull/18#issuecomment-721160985], and it 
    looks much better pre-formatted
    [https://github.com/dscho/git/pull/18#issuecomment-721167209] (even if
    we unfortunately lose the direct link to the commit
    [https://github.com/dscho/git/commit/68317764849af81b17c4b31906da20bdf2c52082]
    ).

What is shown in the log are lines from the source files that were
checked, and we expect our source files are shown and edited in
monospace with tabwidth=8, I think it does make sense to force the
"pre-formatted" output.

Thanks.