Try to fix intermittently failing test case

This test fails intermittently due to taskill reporting failure to kill
the process (because it already has been terminated).  We increase the
sleep time, to hopefully prevent that from happening again.

Author: cmb69

ext/standard/tests/streams/bug78883.phpt

@@ -17,7 +17,7 @@ $cmd = 'cmd.exe "/c START ^"^" /WAIT ' . PHP_BINARY . ' -r ^"var_dump(fgets(STDI
 $proc = proc_open($cmd, $descriptorspec, $pipes);
 var_dump(is_resource($proc));
 $pid = proc_get_status($proc)['pid'];
-sleep(1);
+sleep(2);
 $bug_is_present = !proc_get_status($proc)['running'];
 if (!$bug_is_present) {
 	// if the bug is not present, it will hang waiting for stdin,