Shrink another large image

This image is only used for testing `BITMAPV5HEADER` support in
`getimagesize()` (see bf9ad4e). Therefore it is not necessary to have
a big image; a single pixel is sufficient.

Author: cmb69

ext/standard/tests/image/getimagesize.phpt

@@ -42,13 +42,13 @@ array(13) {
   ["test1bpix.bmp"]=>
   array(6) {
     [0]=>
-    int(500)
+    int(1)
     [1]=>
-    int(345)
+    int(1)
     [2]=>
     int(6)
     [3]=>
-    string(24) "width="500" height="345""
+    string(20) "width="1" height="1""
     ["bits"]=>
     int(32)
     ["mime"]=>