ChangeUtil: Remove javadoc references to deprecated JGit methods

The descriptions are detailed and accurate enough without this
historical note.

Change-Id: If942039c703e3fbd83a16875d083dc3513f50ccc
diff --git a/java/com/google/gerrit/server/ChangeUtil.java b/java/com/google/gerrit/server/ChangeUtil.java
index 571f322..a13f105 100644
--- a/java/com/google/gerrit/server/ChangeUtil.java
+++ b/java/com/google/gerrit/server/ChangeUtil.java
@@ -50,8 +50,7 @@
   /**
    * Get the next patch set ID from a previously-read map of all refs.
    *
-   * @param allRefs map of full ref name to ref, in the same format returned by {@link
-   *     org.eclipse.jgit.lib.RefDatabase#getRefs(String)} when passing {@code ""}.
+   * @param allRefs map of full ref name to ref.
    * @param id previous patch set ID.
    * @return next unused patch set ID for the same change, skipping any IDs whose corresponding ref
    *     names appear in the {@code allRefs} map.
@@ -69,9 +68,7 @@
    *
    * @param changeRefs map of ref suffix to SHA-1, where the keys are ref names with the {@code
    *     refs/changes/CD/ABCD/} prefix stripped. All refs should be under {@code id}'s change ref
-   *     prefix. The keys match the format returned by {@link
-   *     org.eclipse.jgit.lib.RefDatabase#getRefs(String)} when passing the appropriate {@code
-   *     refs/changes/CD/ABCD}.
+   *     prefix.
    * @param id previous patch set ID.
    * @return next unused patch set ID for the same change, skipping any IDs whose corresponding ref
    *     names appear in the {@code changeRefs} map.