fix: can not change the shards clusters count if restored from a backup

Author: teoincontatto

stackgres-k8s/src/operator/src/main/java/io/stackgres/operator/conciliation/factory/shardedcluster/StackGresShardedClusterForUtil.java

@@ -377,7 +377,8 @@ void setInitialData(
         && initialData.getRestore().getFromBackup().getName() != null
         && cluster.getStatus() != null
         && cluster.getStatus().getSgBackups() != null
-        && !cluster.getStatus().getSgBackups().isEmpty()) {
+        && !cluster.getStatus().getSgBackups().isEmpty()
+        && index < cluster.getStatus().getSgBackups().size()) {
       var fromBackup = initialData
           .getRestore().getFromBackup();
       var restoreFromBackupBuilder = new StackGresClusterRestoreFromBackupBuilder()