Use strlen in empty string check, fix test comment

Author: ankith26

src_c/imageext.c

@@ -226,7 +226,7 @@ imageext_load_animation(PyObject *self, PyObject *arg, PyObject *kwargs)
     }
 
     if (name) { /* override extension with namehint if given */
-        type = (name[0] != '\0') ? iext_find_extension(name) : NULL;
+        type = (strlen(name) != 0) ? iext_find_extension(name) : NULL;
     }
     else { /* Otherwise type should be whatever ext is, even if ext is NULL */
         type = ext;

test/image_test.py

@@ -1362,7 +1362,7 @@ def test_load_sized_svg_erroring(self):
 
     @unittest.skipIf(
         pygame.image.get_sdl_image_version() < (2, 6, 0),
-        "load_sized_svg requires SDL_image 2.6.0+",
+        "load_animation requires SDL_image 2.6.0+",
     )
     def test_load_animation(self):
         # test loading from a file