fix test

This fail has nothing together with any changes in run-tests.php
Using run-tests.php from the 5.5 branch brings the same result. So
merely it is about how PHP7 handles and buffers errors.

tests/run-test/test008.phpt

@@ -16,18 +16,15 @@ var_dump(ini_get('display_errors'));
 var_dump(ini_get('error_reporting'));
 var_dump(ini_get('log_errors'));
 var_dump(ini_get('track_errors'));
-ini_set('display_errors', 0);
+ini_set('display_errors', "0");
 var_dump(ini_get('display_errors'));
-var_dump($php_errormsg);
 $error = 1 / 0;
 var_dump($php_errormsg);
 ?>
 --EXPECTF--
-%s: %sivision by zero in %s on line %d
 string(1) "1"
-string(4) "8191"
+string(5) "32767"
 string(1) "0"
 string(1) "1"
 string(1) "0"
 string(%d) "%sivision by zer%s"
-string(%d) "%sivision by zer%s"