Fix go-header usage

[syndbg]

There's a known behavior of YAML template blocks using | that they insert a trailing newline.
To remove it add - a.k.a block chomping indicator.

This would address some of the "weird" copyright header linting offenses that happen by following the example golangci-lint config by heart.

pkg/base64/service.go:13:34: Missed string: (goheader)
// limitations under the License.
                                 ^
pkg/hcl/test/testing.go:13:34: Missed string: (goheader)
// limitations under the License.
                                 ^
pkg/ini/service.go:13:34: Missed string: (goheader)
// limitations under the License.
                                 ^

[boring-cyborg]

Hey, thank you for opening your first Pull Request !

[CLAassistant]

All committers have signed the CLA.

[SVilgelm]

Looks good to me. Thank you

[golangci-automator]

Hey, @syndbg — we just merged your PR to golangci-lint! 🔥🚀

golangci-lint is built by awesome people like you. Let us say “thanks”: we just invited you to join the GolangCI organization on GitHub.
This will add you to our team of maintainers. Accept the invite by visiting this link.

By joining the team, you’ll be able to label issues, review pull requests, and merge approved pull requests.
More information about contributing is here.

Thanks again!