Fixed JSON input stream file is read twice.

main/src/main/java/com/ongres/pgio/main/Main.java

@@ -244,7 +244,7 @@ public class Main {
       JsonValue groups = Json.createReader(inputStream).readValue();
       
       if (groups.getValueType() == ValueType.ARRAY) {
-        Json.createReader(inputStream).readArray().forEach(element -> {
+        groups.asJsonArray().forEach(element -> {
           if (element.getValueType() == ValueType.OBJECT) {
             appendFromObject(builder, element.asJsonObject());
           }