Update golang

Changes:

- https://github.com/docker-library/golang/commit/7315f56: Merge pull request https://github.com/docker-library/golang/pull/319 from infosiftr/stretch-1.14
- https://github.com/docker-library/golang/commit/dd09f36: Add "stretch" variant of 1.14-rc

library/golang

@@ -11,6 +11,11 @@ Architectures: amd64, arm32v7, arm64v8, i386, ppc64le, s390x
 GitCommit: 06bc0446f48dfda05b3548bd1f64eb108471fc6b
 Directory: 1.14-rc/buster
 
+Tags: 1.14rc1-stretch, 1.14-rc-stretch, rc-stretch
+Architectures: amd64, arm32v7, arm64v8, i386, ppc64le, s390x
+GitCommit: dd09f367e097e0bd45467652072c3951c37280cb
+Directory: 1.14-rc/stretch
+
 Tags: 1.14rc1-alpine3.11, 1.14-rc-alpine3.11, rc-alpine3.11, 1.14rc1-alpine, 1.14-rc-alpine, rc-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
 GitCommit: 06bc0446f48dfda05b3548bd1f64eb108471fc6b