Bump gopkg.in/bblfsh/sdk.v2 from 2.16.3 to 2.16.4

Bumps [gopkg.in/bblfsh/sdk.v2](https://github.com/bblfsh/sdk) from 2.16.3 to 2.16.4. - [Release notes](https://github.com/bblfsh/sdk/releases) - [Commits](bblfsh/sdk@v2.16.3...v2.16.4) Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support