[FIX] Solve weave/rest-smtp-sink: Docker image manifest v2 schema 1 deprecation issue (#2152)

cf: https://docs.docker.com/engine/deprecated/#pushing-and-pulling-with-image-manifest-v2-schema-1

Use a rebuilt image would be the trick.
diff --git a/server/testing/src/main/java/org/apache/james/util/docker/Images.java b/server/testing/src/main/java/org/apache/james/util/docker/Images.java
index 704bc34..d5eb146 100644
--- a/server/testing/src/main/java/org/apache/james/util/docker/Images.java
+++ b/server/testing/src/main/java/org/apache/james/util/docker/Images.java
@@ -20,7 +20,7 @@
 package org.apache.james.util.docker;
 
 public interface Images {
-    String FAKE_SMTP = "weave/rest-smtp-sink:latest";
+    String FAKE_SMTP = "quanth99/rest-smtp-sink:1.0"; // Original Dockerfile: https://github.com/ambled/rest-smtp-sink/blob/master/Dockerfile
     String RABBITMQ = "rabbitmq:3.8.18-management";
     String ELASTICSEARCH_2 = "elasticsearch:2.4.6";
     String ELASTICSEARCH_6 = "docker.elastic.co/elasticsearch/elasticsearch:6.3.2";