fix: Relax assignment of backup_configuration when operating as a replica (#589)

Author: OscarVanL

modules/mysql/main.tf

@@ -70,10 +70,10 @@ resource "google_sql_database_instance" "default" {
     connector_enforcement       = local.connector_enforcement
 
     dynamic "backup_configuration" {
-      for_each = var.master_instance_name != null ? [] : [var.backup_configuration]
+      for_each = [var.backup_configuration]
       content {
         binary_log_enabled             = local.binary_log_enabled
-        enabled                        = local.backups_enabled
+        enabled                        = local.backups_enabled && var.master_instance_name == null ? true : false
         start_time                     = lookup(backup_configuration.value, "start_time", null)
         location                       = lookup(backup_configuration.value, "location", null)
         transaction_log_retention_days = lookup(backup_configuration.value, "transaction_log_retention_days", null)