Remove some fully qualified function calls

PhpStorm can't see these or understand how they are being called, which is very annoying for bug hunting. Additionally, we already have the CodeOptimizer for this.

src/pocketmine/Server.php

@@ -2162,7 +2162,7 @@ class Server{
 		$this->logger->logException($e, $trace);
 
 		$lastError = [
-			"type" => \get_class($e),
+			"type" => get_class($e),
 			"message" => $errstr,
 			"fullFile" => $e->getFile(),
 			"file" => $errfile,