MAGETWO-70746: Decrease floating precision #10245

 - Merge Pull Request #10245 from flancer64/magento2:patch-2
 - Merged commits:
   1. 7478f20

Author: Oleksii Korshenko

app/bootstrap.php

@@ -63,5 +63,5 @@
 date_default_timezone_set('UTC');
 
 /*  Adjustment of precision value for several versions of PHP */
-ini_set('precision', 17);
-ini_set('serialize_precision', 17);
+ini_set('precision', 15);
+ini_set('serialize_precision', 15);