SshdSession: close channel gracefully

Close the channel gracefully to give the server a chance to clean up
properly on its side.

Bug: 565854
Change-Id: Iedda5af3b97c8321f08f7ce854274cbb30e401de
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/transport/sshd/SshdSession.java

@@ -242,7 +242,7 @@ public class SshdSession implements RemoteSession {
 		@Override
 		public void destroy() {
 			if (channel.isOpen()) {
-				channel.close(true);
+				channel.close(false);
 			}
 		}
 	}