Add missing @since tags on new API constants

Change-Id: Ia8b861da07fba99644ccc9eb5578a46cc39600a1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/PackConfig.java

@@ -76,15 +76,15 @@ public class PackConfig {
 
 	/**
 	 * Default value of keep old packs option: {@value}
-	 *
 	 * @see #setPreserveOldPacks(boolean)
+	 * @since 4.7
 	 */
 	public static final boolean DEFAULT_PRESERVE_OLD_PACKS = false;
 
 	/**
 	 * Default value of prune old packs option: {@value}
-	 *
 	 * @see #setPrunePreserved(boolean)
+	 * @since 4.7
 	 */
 	public static final boolean DEFAULT_PRUNE_PRESERVED = false;