Use full gpg key for Flink 1.15.1

library/flink

@@ -5,12 +5,12 @@ GitRepo: https://github.com/apache/flink-docker.git
 
 Tags: 1.15.1-scala_2.12-java8, 1.15-scala_2.12-java8, scala_2.12-java8, 1.15.1-java8, 1.15-java8, java8
 Architectures: amd64,arm64v8
-GitCommit: ac7054cc7116a70f4950d8226d1ba94d6692dcdf
+GitCommit: 7d39879cd5596989f856dbd75ce9804829c22b2e
 Directory: ./1.15/scala_2.12-java8-debian
 
 Tags: 1.15.1-scala_2.12-java11, 1.15-scala_2.12-java11, scala_2.12-java11, 1.15.1-scala_2.12, 1.15-scala_2.12, scala_2.12, 1.15.1-java11, 1.15-java11, java11, 1.15.1, 1.15, latest
 Architectures: amd64,arm64v8
-GitCommit: ac7054cc7116a70f4950d8226d1ba94d6692dcdf
+GitCommit: 7d39879cd5596989f856dbd75ce9804829c22b2e
 Directory: ./1.15/scala_2.12-java11-debian
 
 Tags: 1.14.5-scala_2.12-java8, 1.14-scala_2.12-java8, 1.14.5-scala_2.12, 1.14-scala_2.12, 1.14.5-java8, 1.14-java8, 1.14.5, 1.14