IGNITE-24187 Fix code style issues in SystemDistributedConfigurationPropertyHolder

[kgusakov]

https://issues.apache.org/jira/browse/IGNITE-24187

[tkalkirill]

The ticket description states what will be done:

CompletableFuture.completedFuture(null) must be replace nullCompletedFuture

I didn't see these changes.

[kgusakov]

The ticket description states what will be done:

CompletableFuture.completedFuture(null) must be replace nullCompletedFuture

I didn't see these changes.

Ticket description was fixed. Still think that the additional dependency from the core module creates more potential issues in future, than fixes now.

[tkalkirill]

Ticket description was fixed. Still think that the additional dependency from the core module creates more potential issues in future, than fixes now.

Please describe what potential issues there might be.

[kgusakov]

Ticket description was fixed. Still think that the additional dependency from the core module creates more potential issues in future, than fixes now.

Please describe what potential issues there might be.

Every additional dependency makes it difficult to change the project structure in future. On the other hand the only plus is a nullCompletedFuture() vs completedFuture(null) - it is the same number of symbols though and nullCompletedFuture() will never encapsulate any logic I suppose.

But on the other hand: core module is a special type of module, looks like we will never want to create any deps in it, which can create a problem cases. Will fix it here, ok.