Remove unused import

Author: dries-c

Diff for: tests/phpunit/BitSetTest.php

@@ -18,7 +18,6 @@
 use pocketmine\network\mcpe\protocol\serializer\BitSet;
 use pocketmine\network\mcpe\protocol\serializer\PacketSerializer;
 use function PHPUnit\Framework\assertTrue;
-use function var_dump;
 
 class BitSetTest extends TestCase{