Add missing @since tag for RevCommit#parents introduced in 61b4d105e4

Change-Id: I3b5c22eea7d0af5464c7df7a7cd855ea08029853

org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java

@@ -106,6 +106,8 @@ public static RevCommit parse(RevWalk rw, byte[] raw) throws IOException {
 	 * Avoid accessing this field directly. Use method
 	 * {@link RevCommit#getParents()} instead. RevCommit does not allow parents
 	 * to be overridden and altering parent(s) is not supported.
+	 *
+	 * @since 6.3
 	 */
 	protected RevCommit[] parents;