fix unused @SuppressWarnings("checkstyle:UnusedLocalVariable")

Author: Vincent Potucek

its/core-it-support/core-it-plugins/maven-it-plugin-configuration/src/main/java/org/apache/maven/plugin/coreit/PropertiesUtil.java

@@ -104,9 +104,7 @@ public static void serialize(Properties props, String key, Object value) {
         } else if (value instanceof Map) {
             Map map = (Map) value;
             props.setProperty(key, Integer.toString(map.size()));
-            @SuppressWarnings("checkstyle:UnusedLocalVariable")
-            int i = 0;
-            for (Iterator it = map.keySet().iterator(); it.hasNext(); i++) {
+            for (Iterator it = map.keySet().iterator(); it.hasNext();) {
                 Object k = it.next();
                 Object v = map.get(k);
                 serialize(props, key + "." + k, v);