Update Javadoc since tags.
diff --git a/src/main/java/org/apache/commons/configuration2/ImmutableConfiguration.java b/src/main/java/org/apache/commons/configuration2/ImmutableConfiguration.java
index ba371d0..1ba0052 100644
--- a/src/main/java/org/apache/commons/configuration2/ImmutableConfiguration.java
+++ b/src/main/java/org/apache/commons/configuration2/ImmutableConfiguration.java
@@ -343,7 +343,7 @@
      *
      * @throws org.apache.commons.configuration2.ex.ConversionException is thrown if the key maps to an object that is not a
      *         String.
-     * @since 2.8
+     * @since 2.8.0
      */
     default <T extends Enum<T>> T getEnum(final String key, final Class<T> enumType) {
         try {
@@ -365,7 +365,7 @@
      *
      * @throws org.apache.commons.configuration2.ex.ConversionException is thrown if the key maps to an object that is not a
      *         Enum.
-     * @since 2.8
+     * @since 2.8.0
      */
     default <T extends Enum<T>> T getEnum(final String key, final Class<T> enumType, final T defaultValue) {
         final String strValue = getString(key, null);