add 'all_ips_string' to list of read only fields in SliverAdmin
diff --git a/planetstack/core/admin.py b/planetstack/core/admin.py
index 3931f75..e34619c 100644
--- a/planetstack/core/admin.py
+++ b/planetstack/core/admin.py
@@ -1108,7 +1108,7 @@
     fieldsets = [
         ('Sliver Details', {'fields': ['backend_status_text', 'slice', 'deployment', 'node', 'all_ips_string', 'instance_id', 'instance_name', 'flavor', 'image', 'ssh_command'], 'classes': ['suit-tab suit-tab-general'], })
     ]
-    readonly_fields = ('backend_status_text', 'ssh_command', )
+    readonly_fields = ('backend_status_text', 'ssh_command', 'all_ips_string')
     list_display = ['backend_status_icon', 'all_ips_string', 'instance_id', 'instance_name', 'slice', 'flavor', 'image', 'node', 'deployment']
     list_display_links = ('backend_status_icon', 'all_ips_string',)