Guard against NPE in loadData() when called before onEnable()

[Copilot]

CraftEngine (and Nexo/ItemsAdder) fire their reload events during server startup before AOneBlock.onEnable() has run, meaning oneBlockManager is still null when loadData() is invoked via the event listener — causing a NullPointerException.

Changes

• AOneBlock.loadData() — added an early-return null guard for oneBlockManager. When the manager hasn't been initialized yet, loadData() is a no-op; phases load normally during onEnable().

public boolean loadData() {
    if (oneBlockManager == null) {
        // Not yet initialized — phases will load during onEnable()
        return false;
    }
    // ...
}

• AOneBlockTest — added testLoadDataWhenManagerIsNull to assert that calling loadData() before onEnable() returns false without throwing.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud