nimbus-era-files: use --network flag to fix errors

Changes to default runtime config have caused errors like this:
```
FAT Could not load head state, database corrupt? tid=3639597 file=blockchain_dag.nim:920 head=e7d4f3b7:4636671 tail=4d611d5b:0 genesis=4d611d5b:0
```

Signed-off-by: Jakub Sokołowski <jakub@status.im>

ansible/group_vars/nimbus.mainnet.yml

@@ -90,6 +90,7 @@ nimbus_db_purge_trusted_node_sync_enabled: '{{ node.get("db_sync", false) }}'
 # ERA files geneartion.
 nimbus_era_files_timer_enabled: '{{ (nodes_layout[hostname]|length) > 1 }}'
 nimbus_era_files_timer_path: '/data/era'
+nimbus_era_files_network: '{{ beacon_node_network }}'
 # FIXME: Not pretty, since hardcoded, but the simplest way to do it right now.
 nimbus_era_files_node_service_path: '/data/beacon-node-{{ beacon_node_network }}-stable-01'
 nimbus_era_files_nclidb_path: '{{ nimbus_era_files_node_service_path }}/repo/build/ncli_db'

ansible/mainnet.yml

@@ -38,7 +38,7 @@
     - { role: infra-role-geth,              tags: [ infra-role-geth ] }
     - { role: infra-role-geth-exporter,     tags: [ infra-role-geth-exporter ] }
     - { role: get-geth-api-urls,            tags: [ get-geth-api-urls ] }
-    - { role: nimbus-era-files,             tags: [ nimbus-era-file ] }
+    - { role: nimbus-era-files,             tags: [ nimbus-era-files ] }
   tasks:
     - include_role: name=infra-role-beacon-node-linux
       tags: [ beacon-node, infra-role-beacon-node-linux ]

ansible/roles/nimbus-era-files/README.md

@@ -13,6 +13,7 @@ nimbus_era_files_timer_name: 'nimbus-era-files-update'
 nimbus_era_files_timer_path: '/data/era'
 nimbus_era_files_nclidb_path: '/data/nimbus/repo/build/bin/ncli_db'
 nimbus_era_files_db_path: '/data/nimbus/data/db'
+#nimbus_era_files_network: 'prater'
 ```
 
 # Management

ansible/roles/nimbus-era-files/defaults/main.yml

@@ -13,3 +13,4 @@ nimbus_era_files_timer_script: '{{ nimbus_era_files_timer_path }}/update.sh'
 # Mandatory
 #nimbus_era_files_nclidb_path: ~
 #nimbus_era_files_db_path: ~
+#nimbus_era_files_network: ~

ansible/roles/nimbus-era-files/tasks/main.yml

@@ -21,4 +21,5 @@
     systemd_timer_ionice_class:      '{{ nimbus_era_files_timer_ionice_class }}'
     systemd_timer_work_dir:          '{{ nimbus_era_files_timer_path }}'
     systemd_timer_script_path:       '{{ nimbus_era_files_nclidb_path }}'
-    systemd_timer_script_args:       'exportEra --db={{ nimbus_era_files_db_path }}'
+    systemd_timer_script_args: >
+      --network={{ nimbus_era_files_network }} exportEra --db={{ nimbus_era_files_db_path }}