Fix test portability

Author: weltling

ext/iconv/tests/bug76249.phpt

@@ -7,12 +7,14 @@ Bug #76249 (stream filter convert.iconv leads to infinite loop on invalid sequen
 $fh = fopen('php://memory', 'rw');
 fwrite($fh, "abc");
 rewind($fh);
-stream_filter_append($fh, 'convert.iconv.ucs-2/utf8//IGNORE', STREAM_FILTER_READ, []);
+if (false === @stream_filter_append($fh, 'convert.iconv.ucs-2/utf8//IGNORE', STREAM_FILTER_READ, [])) {
+	stream_filter_append($fh, 'convert.iconv.ucs-2/utf-8//IGNORE', STREAM_FILTER_READ, []);
+}
 $a = stream_get_contents($fh);
 var_dump(strlen($a));
 ?>
 DONE
 --EXPECTF--
-Warning: stream_get_contents(): iconv stream filter ("ucs-2"=>"utf8//IGNORE"): invalid multibyte sequence in %sbug76249.php on line %d
+Warning: stream_get_contents(): iconv stream filter ("ucs-2"=>"utf%A8//IGNORE"): invalid multibyte sequence in %sbug76249.php on line %d
 int(3)
 DONE