Add recover protection to Go method

[FishGoddess]

A Goroutine without recover protection will panic if something wrong happended, so I add recover to Go().

PTAL, thanks :)

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[FishGoddess]

@googlebot I signed it!

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This PR (HEAD: 62ef034) has been imported to Gerrit for code review.

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Patch Set 1:

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[gopherbot]

Message from Bryan C. Mills:

Patch Set 1: Code-Review-2

(1 comment)

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[gopherbot]

Message from 叶子杰:

Patch Set 1:

(1 comment)

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Please don’t reply on this GitHub thread. Visit golang.org/cl/348889.
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