https://build.spring.io/browse/INT-MASTER-468/
Looks like demand in the `FluxTake` isn't honored:
```
public void request(long n) {
if (wip != 0) {
s.request(n);
}
else if (WIP.compareAndSet(this, 0, 1)) {
if (n >= this.n) {
s.request(Long.MAX_VALUE);
}
else {
s.request(n);
}
}
}
````
It isn't clear why we request from upstream `Long.MAX_VALUE`, if we have only strong `n` limit
So, revert to the `secondSubscriberLatch` and don't send the next message until the subscription from the second `Flux`
61e77435ab