message: Fix swagger->sdk tag for go
diff: @@ -147,7 +147,7 @@ output-folder: $(go-sdk-folder)/services/mysql/mgmt/2017-12-01-preview/mysql
  These settings apply only when `--tag=package-2017-12-01 --go` is specified on the command line.
  Please also specify `--go-sdk-folder=<path to the root directory of your azure-sdk-for-go clone>`.
  -``` yaml $(tag) == 'package-2017-12-01-preview' && $(go)
  +``` yaml $(tag) == 'package-2017-12-01' && $(go)
  output-folder: $(go-sdk-folder)/services/mysql/mgmt/2017-12-01/mysql
  ```
  