ConsoleCommandSender: ensure that PermissibleBase doesn't leak

if recalculatePermissions() was called, the PermissionManager will reference it, preventing it from being GC'd.

src/command/ConsoleCommandSender.php

@@ -87,4 +87,9 @@ class ConsoleCommandSender implements CommandSender{
 		}
 		$this->lineHeight = $height;
 	}
+
+	public function __destruct(){
+		//permission subscriptions need to be cleaned up explicitly
+		$this->perm->destroyCycles();
+	}
 }