Make Redis Array tests work on 32-bit.

The custom key distribution function was returning negative
ring offsets. This fix makes sure we always return positive or zero.

Author: nicolasff

tests/array-tests.php

@@ -95,9 +95,9 @@ public function testKeyLocality() {
 
 	public function customDistributor($key)
 	{
-		$a = unpack("N*", md5($key, true));;
+		$a = unpack("N*", md5($key, true));
 		global $newRing;
-		$pos = $a[1] % count($newRing);
+		$pos = abs($a[1]) % count($newRing);
 
 		return $pos;
 	}