Snippets: remove the comma from the placeholder in forr

[imbant]

When using "forr" snippet,
the comma in the "_, " placeholder will be deleted
if user edit the placeholder.

So the comma should not be part of the placeholder

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[gopherbot]

Message from Gopher Robot:

Patch Set 1:

(1 comment)

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Patch Set 1:

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[gopherbot]

Message from my x:

Patch Set 1:

(2 comments)

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