Remove non supported architectures by the base image

Only keep amd64 architecture that is the only supported by the base
image tomcat:8.5-jdk8.

library/geonetwork

@@ -1,9 +1,9 @@
-# this file is generated via https://github.com/geonetwork/docker-geonetwork/blob/f5f6c7c39d1a3d5260a68d21086e062a511bf487/generate-stackbrew-library.sh
+# this file is generated via https://github.com/geonetwork/docker-geonetwork/blob/27a30d076d7358917d9f0d06577ff856f2e8e2b6/generate-stackbrew-library.sh
 
 Maintainers: Joana Simoes <[email protected]> (@doublebyte1),
      Juan Luis Rodriguez <[email protected]> (@juanluisrp)
 GitRepo: https://github.com/geonetwork/docker-geonetwork
-Architectures: amd64, arm32v5, arm32v7, arm64v8, i386, ppc64le, s390x
+Architectures: amd64
 
 Tags: 3.6.0, 3.6
 GitCommit: e249c6031a55559392204a2c3ef8e8f8d11545a5