WebP/Lossy: Use correct test image for coefficient skipping

I somehow added the wrong image here. 4.webp is the one described
by the comment in the test. Now test actually uses the image it
claims to use.

No behavior change.

Tests/LibGfx/TestImageDecoder.cpp

@@ -404,13 +404,13 @@ TEST_CASE(test_webp_extended_lossy_uncompressed_alpha)
     EXPECT_EQ(frame.image->get_pixel(355, 106), Gfx::Color(0, 0, 0, 0));
 }
 
-TEST_CASE(test_webp_lossy_5)
+TEST_CASE(test_webp_lossy_4)
 {
     // This is https://commons.wikimedia.org/wiki/File:Fr%C3%BChling_bl%C3%BChender_Kirschenbaum.jpg,
     // under the Creative Commons Attribution-Share Alike 3.0 Unported license. The image was re-encoded
     // as webp at https://developers.google.com/speed/webp/gallery1 and the webp version is from there.
     // No other changes have been made.
-    auto file = MUST(Core::MappedFile::map(TEST_INPUT("5.webp"sv)));
+    auto file = MUST(Core::MappedFile::map(TEST_INPUT("4.webp"sv)));
     EXPECT(Gfx::WebPImageDecoderPlugin::sniff(file->bytes()));
     auto plugin_decoder = MUST(Gfx::WebPImageDecoderPlugin::create(file->bytes()));
     MUST(plugin_decoder->initialize());
@@ -419,13 +419,13 @@ TEST_CASE(test_webp_lossy_5)
     EXPECT(!plugin_decoder->is_animated());
     EXPECT(!plugin_decoder->loop_count());
 
-    EXPECT_EQ(plugin_decoder->size(), Gfx::IntSize(1024, 752));
+    EXPECT_EQ(plugin_decoder->size(), Gfx::IntSize(1024, 772));
 
     auto frame = MUST(plugin_decoder->frame(0));
-    EXPECT_EQ(frame.image->size(), Gfx::IntSize(1024, 752));
+    EXPECT_EQ(frame.image->size(), Gfx::IntSize(1024, 772));
 
     // This image tests macroblocks that have `skip_coefficients` set to true, and it test a boolean entropy decoder edge case.
-    EXPECT_EQ(frame.image->get_pixel(923, 576), Gfx::Color(0xab, 0x40, 0x14, 255));
+    EXPECT_EQ(frame.image->get_pixel(780, 570), Gfx::Color(0x72, 0xc8, 0xf6, 255));
 }
 
 TEST_CASE(test_webp_extended_lossless)