Bug fix: fixed the problem with the HTTP/1.1 async protocol handler i…

…ncorrectly reporting its state as CLOSED immediately after its instantiation until #onConnect event has been triggered

httpcore5/src/main/java/org/apache/hc/core5/http/impl/nio/AbstractHttp1StreamDuplexer.java

@@ -559,7 +559,7 @@ public void close(final CloseMode closeMode) {
 
     @Override
     public boolean isOpen() {
-        return connState == ConnectionState.ACTIVE;
+        return connState.compareTo(ConnectionState.ACTIVE) <= 0;
     }
 
     @Override