No function changes. Cleanup console command cleanup

app/Console/Commands/Debug/ZoneCheck.php

@@ -14,7 +14,7 @@ class ZoneCheck extends Command
 
 	protected $description = 'Check that the addresses in a zone are configured correctly';
 
-	public function handle()
+	public function handle(): int
 	{
 		$do = Domain::where('name',$this->argument('domain'))->singleOrFail();
 
@@ -42,6 +42,6 @@ class ZoneCheck extends Command
 			}));
 		}
 
-		return Command::SUCCESS;
+		return self::SUCCESS;
 	}
 }