[Segment Replication] Cancellation check before send files to prevent…

… segrep round

Signed-off-by: Suraj Singh <surajrider@gmail.com>

server/src/main/java/org/opensearch/indices/replication/SegmentReplicationSourceHandler.java

@@ -136,7 +136,7 @@ public synchronized void sendFiles(GetSegmentFilesRequest request, ActionListene
                     timer.time()
                 );
             };
-
+            cancellableThreads.checkForCancel();
             final IndexShardRoutingTable routingTable = shard.getReplicationGroup().getRoutingTable();
             ShardRouting targetShardRouting = routingTable.getByAllocationId(request.getTargetAllocationId());
             if (targetShardRouting == null) {