Update openjdk

Changes:

- docker-library/openjdk@b7ab504: Merge pull request docker-library/openjdk#296 from infosiftr/12-ga
- docker-library/openjdk@58b0eb3: Update "latest" to OpenJDK 12
- docker-library/openjdk@311e8bb: Update to 13-ea+12
- docker-library/openjdk@3ba705f: Update to 13-ea+13
- docker-library/openjdk@d42099b: Update to 7u211, debian 7u211-2.6.17-1~deb8u1
- docker-library/openjdk@aea0404: Update to 12
- docker-library/openjdk@b8ce9ef: Update to 8u212, debian 8u212-b01-1~deb9u1
- docker-library/openjdk@d4ecf99: Merge pull request docker-library/openjdk#294 from luiszimmermann/nss-fix
- docker-library/openjdk@79a6e42: Force install nss in Alpine
- docker-library/openjdk@cb138b5: Update to 13-ea+12