fix(go): "if err != nil" (ir~) (#522)

The snippets in go.json works great, except this one. It causes an error.

snippets/go.json

@@ -116,7 +116,7 @@
     },
     "if err != nil": {
         "prefix": "ir",
-        "body": "if err != nil {\n\t${1:return ${2:nil, }${3:err}}\n}",
+        "body": "if err != nil {\n\treturn ${1:nil}, ${2:err}\n}",
         "description": "Snippet for if err != nil"
     },
     "fmt.Println": {