Tweak async socket sequence number emission.

Matches a fix in MoarVM. Enables fixing various data loss bugs.

Author: jnthn

src/vm/jvm/runtime/org/perl6/nqp/io/AsyncSocketHandle.java

@@ -194,8 +194,7 @@ public void completed(Integer numRead, AsyncTaskInstance task) {
 
                 try {
                     if (numRead == -1) {
-                        task.seq = -1;
-                        callback(curTC, task, -1, Str, Null);
+                        callback(curTC, task, task.seq, Str, Null);
                     } else {
                         readBuffer.flip();
                         SixModelObject decoded = decoder.decode(tc, readBuffer, numRead);