(docs)remove dead link

[MWGitHub]

This removes a dead link (https://bitbucket.org/alexg/syntaxhighlighter/issues/177/superfluous-vertical-scrollbars-in-chrome) which linked to an issue on Bitbucket that no longer exists due to the project moving to GitHub.

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[MWGitHub]

I signed it!

[googlebot]

CLAs look good, thanks!

[Narretz]

What's the github project name? Maybe the workaround can be removed completely.

[MWGitHub]

The github project's name is SyntaxHighlighter and can be found here:
https://github.com/syntaxhighlighter/syntaxhighlighter