scylla-monitoring: add a missing "| default('')" in dc_to_node_list calculation

Signed-off-by: Vlad Zolotarov <[email protected]>

Author: vladzcloudius

ansible-scylla-monitoring/tasks/common.yml

@@ -103,7 +103,7 @@
     # Resulting map -> {'-dc dc1': [node1, node2, node3], '-dc dc2': [node4, node5, node6]}
     - name: Create a map from dc to its list of nodes
       set_fact:
-        dc_to_node_list: "{{ dc_to_node_list | default({}) | combine( {'-dc ' + hostvars[item]['dc'] + hostvars[item]['dc_suffix']: (dc_to_node_list | default({}))['-dc ' + hostvars[item]['dc'] + hostvars[item]['dc_suffix'] | default('')] | default([]) + [item]} ) }}"
+        dc_to_node_list: "{{ dc_to_node_list | default({}) | combine( {'-dc ' + hostvars[item]['dc'] + hostvars[item]['dc_suffix'] | default(''): (dc_to_node_list | default({}))['-dc ' + hostvars[item]['dc'] + hostvars[item]['dc_suffix'] | default('')] | default([]) + [item]} ) }}"
       loop: "{{ groups['scylla'] }}"
 
     # Resulting str -> "-dc dc1:node1,node2,node3 -dc dc2:node4,node5,node6"