Aptly: --acquire-by-hash systematically

Change-Id: I76a05bb837f0f3169ef574fe6d97970b8a881040
diff --git a/src/com/mirantis/mk/Aptly.groovy b/src/com/mirantis/mk/Aptly.groovy
index c566a16..ddbe4fd 100644
--- a/src/com/mirantis/mk/Aptly.groovy
+++ b/src/com/mirantis/mk/Aptly.groovy
@@ -107,7 +107,7 @@
         dumpPublishes(server, timestamp, dumpTarget)
     }
 
-    sh("aptly-publisher --url ${server} promote --source '${source}' --target '${target}' --force-overwrite ${opts}")
+    sh("aptly-publisher --url ${server} promote --acquire-by-hash --source '${source}' --target '${target}' --force-overwrite ${opts}")
 
 }
 
@@ -121,7 +121,7 @@
     if (force_overwrite == true) {
         opts = "${opts} --force-overwrite"
     }
-    sh("aptly-publisher --url ${server} -c ${config} ${opts} publish")
+    sh("aptly-publisher --url ${server} -c ${config} ${opts} --acquire-by-hash publish")
 }
 
 /**