Snippets: remove the comma from the placeholder in forr

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

Change-Id: Ief4e6f24055c75dbb75d413b8fdbdeae39a437c2
GitHub-Last-Rev: 738c0bf
GitHub-Pull-Request: #3602
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/627895
Reviewed-by: Dmitri Shuralyov <[email protected]>
kokoro-CI: kokoro <[email protected]>
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
Commit-Queue: Hyang-Ah Hana Kim <[email protected]>

Author: imbant

extension/snippets/go.json

@@ -77,7 +77,7 @@
 		},
 		"for range statement": {
 			"prefix": "forr",
-			"body": "for ${1:_, }${2:v} := range ${3:v} {\n\t$0\n}",
+			"body": "for ${1:_}, ${2:v} := range ${3:v} {\n\t$0\n}",
 			"description": "Snippet for a for range loop"
 		},
 		"channel declaration": {