Bug 574017 - Version bump up for 4.21

Change-Id: I54a98674c375377878c9a42dc5635fb32a21656b
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.debug/+/182679
Tested-by: JDT Bot <jdt-bot@eclipse.org>
Reviewed-by: Sarika Sinha <sarika.sinha@in.ibm.com>
6 files changed