puppet: Postgres replication should always switch to latest timeline.

Omission of this setting makes resuming after a primary switchover
difficult-to-impossible.  It is the default in PostgreSQL 12.

puppet/zulip/templates/postgresql/10/postgresql.conf.centos.template.erb

@@ -701,6 +701,7 @@ archive_mode = on
 archive_command = '/usr/local/bin/env-wal-g wal-push %p'
 
 # Replica settings (ignored on primary)
+recovery_target_timeline = 'latest'
 hot_standby = on
 <% end -%>
 

puppet/zulip/templates/postgresql/10/postgresql.conf.template.erb

@@ -701,6 +701,7 @@ archive_mode = on
 archive_command = '/usr/local/bin/env-wal-g wal-push %p'
 
 # Replica settings (ignored on primary)
+recovery_target_timeline = 'latest'
 hot_standby = on
 <% end -%>
 

puppet/zulip/templates/postgresql/11/postgresql.conf.template.erb

@@ -701,6 +701,7 @@ archive_mode = on
 archive_command = '/usr/local/bin/env-wal-g wal-push %p'
 
 # Replica settings (ignored on primary)
+recovery_target_timeline = 'latest'
 hot_standby = on
 <% end -%>
 

puppet/zulip/templates/postgresql/12/postgresql.conf.template.erb

@@ -795,6 +795,7 @@ archive_mode = on
 archive_command = '/usr/local/bin/env-wal-g wal-push %p'
 
 # Replica settings (ignored on primary)
+recovery_target_timeline = 'latest'
 hot_standby = on
 <% end -%>
 

puppet/zulip/templates/postgresql/9.5/postgresql.conf.template.erb

@@ -673,6 +673,7 @@ archive_mode = on
 archive_command = '/usr/local/bin/env-wal-g wal-push %p'
 
 # Replica settings (ignored on primary)
+recovery_target_timeline = 'latest'
 hot_standby = on
 <% end -%>
 

puppet/zulip/templates/postgresql/9.6/postgresql.conf.template.erb

@@ -686,6 +686,7 @@ archive_mode = on
 archive_command = '/usr/local/bin/env-wal-g wal-push %p'
 
 # Replica settings (ignored on primary)
+recovery_target_timeline = 'latest'
 hot_standby = on
 <% end -%>