Change storage_backend_network_cidr

The patch chnages storage_backend_network_cidr to the same cidr
as for storage_frontend_network_cidr for instances which are not
connected to this network because only OSD nodes are switched to
both networks.

Related-PROD: PRODX-2799
Change-Id: I08d2ed3403b4a7c926593423e32474abe70d1968
diff --git a/de/heat-templates/env/mstr1-wrkr3-cmp2-gtw0-lma3.yaml b/de/heat-templates/env/mstr1-wrkr3-cmp2-gtw0-lma3.yaml
index aa49136..ad145c6 100644
--- a/de/heat-templates/env/mstr1-wrkr3-cmp2-gtw0-lma3.yaml
+++ b/de/heat-templates/env/mstr1-wrkr3-cmp2-gtw0-lma3.yaml
@@ -28,6 +28,8 @@
   # ephemeral storage because it is used for Ceph bluestore.
   workers_flavor: 'system.compact.openstack.control.ephemeral'
   cmps_flavor: 'system.compact.openstack.control.ephemeral'
+  storage_frontend_network_cidr: '10.12.0.0/24'
+  storage_backend_network_cidr: '10.12.0.0/24'
   hardware_metadata: |
     '00:00:00:00:00:00':
       write_files: