Merge pull request electrolinux#1 from lauripiisang/dev-fixed-getstring

Fixed getString(0) and getStrings(0) null check

Author: lauripiisang

phpQuery/phpQuery/phpQueryObject.php

@@ -502,7 +502,7 @@ public function get($index = null, $callback1 = null, $callback2 = null, $callba
 	 * @todo maybe other name...
 	 */
 	public function getString($index = null, $callback1 = null, $callback2 = null, $callback3 = null) {
-		if ($index)
+		if ($index != null && is_int($index))
 			$return = $this->eq($index)->text();
 		else {
 			$return = array();
@@ -529,7 +529,7 @@ public function getString($index = null, $callback1 = null, $callback2 = null, $
 	 * @todo maybe other name...
 	 */
 	public function getStrings($index = null, $callback1 = null, $callback2 = null, $callback3 = null) {
-		if ($index)
+		if ($index != null && is_int($index))
 			$return = $this->eq($index)->text();
 		else {
 			$return = array();