Replace loose check with a more strict one

The loose check appears to not be necesary. There do not appear to be
differences between systems.

tests/test_pillow.py

@@ -179,11 +179,10 @@ def test_transform_colorspace_to_srgb(self):
         expected_sum2 = [1286116001.0, 1222827100.0, 1144012271.0]
 
         for actual, expected in zip(stat.sum2, expected_sum2):
-            self.assertAlmostEqual(
+            self.assertEqual(
                 actual,
                 expected,
-                delta=1000,
-                msg="The colors in this image deviate too much from the expected values.",
+                msg="The colors in the transformed image don't match with expectations. Did the sample image change or is there a bug?",
             )
 
         # The image should now have a embedded sRGB profile