Redirect dead link in docs

[John2143]

The link previous link exists in the wayback machine (http://web.archive.org/web/20151030063902/https://strongloop.com/strongblog/whats-new-node-js-v0-12-multiple-context-execution/), however on the live page the link is dead. This is the commit message for node that summarizes it well, but maybe the better option is just to remove the link entirely.

[welcome]

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[zeke]

Thanks!

[welcome]

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