Removed racy assert.

JAVA-5856

Author: vbabanin

driver-core/src/main/com/mongodb/internal/connection/TlsChannelStreamFactoryFactory.java

@@ -159,8 +159,6 @@ void start() {
                                 if (markedCompleted) {
                                     Runnable runnable = socketRegistration.attachment;
                                     runnable.run();
-                                } else {
-                                    assertFalse(socketRegistration.socketChannel.isOpen());
                                 }
                             }