Unhardcoding salt master name from cluster model.

It may differ from default and should refer to manageable variable

Prod-Related: PROD-29870

Change-Id: I6735e74a97d6beb3f6fa80327ef85fe27e2bf4f8
(cherry-picked from commit d07ce1349db56b97314c0b7baf3e1e126c3eb06f)
diff --git a/cassandra/backup/client/single.yml b/cassandra/backup/client/single.yml
index 892f92f..0753740 100644
--- a/cassandra/backup/client/single.yml
+++ b/cassandra/backup/client/single.yml
@@ -2,8 +2,6 @@
 - service.cassandra.backup.client
 - system.openssh.client.root
 parameters:
-  _param:
-    cassandra_remote_backup_server: cfg01
   cassandra:
     backup:
       client:
diff --git a/defaults/backup.yml b/defaults/backup.yml
index 66e5173..76bed01 100644
--- a/defaults/backup.yml
+++ b/defaults/backup.yml
@@ -5,3 +5,6 @@
     backup_day_of_month: "*"
     backup_month: "*"
     backup_day_of_week: "*"
+    zookeeper_remote_backup_server: ${_param:infra_config_hostname}
+    cassandra_remote_backup_server: ${_param:infra_config_hostname}
+
diff --git a/defaults/init.yml b/defaults/init.yml
index b7995d8..6c8684c 100644
--- a/defaults/init.yml
+++ b/defaults/init.yml
@@ -49,7 +49,7 @@
     # Other
     salt_control_xenial_image_backend: /var/lib/libvirt/images/backends/xenial.qcow2
     salt_control_trusty_image_backend: /var/lib/libvirt/images/backends/trusty.qcow2
-    salt_minion_ca_host: cfg01.${_param:cluster_domain}
+    salt_minion_ca_host: ${_param:infra_config_hostname}.${_param:cluster_domain}
     # Make sure this global variable is defined everywhere, where used it is already set on cluster level
     cluster_public_host: '127.0.0.1'
     single_address: '127.0.0.1'
diff --git a/zookeeper/backup/client/single.yml b/zookeeper/backup/client/single.yml
index d8eaaac..e1eac1b 100644
--- a/zookeeper/backup/client/single.yml
+++ b/zookeeper/backup/client/single.yml
@@ -2,8 +2,6 @@
 - service.zookeeper.backup.client
 - system.openssh.client.root
 parameters:
-  _param:
-    zookeeper_remote_backup_server: cfg01
   zookeeper:
     backup:
       client: