The init parameter "0" is valid, as in the case of calling the SoftLa…

…yer_Product_Package service. Check for literal null instead of also ignoring "0" in the init parameter.

SoftLayer/SoapClient.class.php

@@ -265,7 +265,7 @@ public static function getClient($serviceName, $id = null, $username = null, $ap
             $soapClient->setAuthentication(self::API_USER, self::API_KEY);
         }
 
-        if ($id != null) {
+        if ($id !== null) {
             $soapClient->setInitParameter($id);
         }