Roll back Ubuntu 14.04 Trusty 20191107 and point to previous 20190515

Due to issues updating and installing packages when ESM repo is added
we are rolling back recent update to Trusty and reverting to 20190515.

For more context see discussions in https://github.com/docker-library/official-images/pull/7029

library/ubuntu

@@ -43,6 +43,11 @@ Tags: 20.04, focal-20191030, focal, devel
 Architectures: amd64, arm32v7, arm64v8, i386, ppc64le, s390x
 Directory: focal
 
+# 20190515 (trusty)
+Tags: 14.04, trusty-20190515, trusty
+Architectures: amd64, arm32v7, arm64v8, i386, ppc64le
+Directory: trusty
+
 # 20191108 (xenial)
 Tags: 16.04, xenial-20191108, xenial
 Architectures: amd64, arm32v7, arm64v8, i386, ppc64le, s390x